Hello,
I want to replace my carbs (hence the title). I want to do this, since the way to access the pilot screw on the stock carbs sucks so badly.
Preferably i would want to have 2 carbs, one with the airscrew on the left side, and another one with the screw on the right.
Are there any kits available for this? or should i just yolo it with a custom build of 2 different carburettors?
Easiest way to do this would be to drill out the plug so that you can access the screw without taking anything apart. Once the plug is removed you can access the screw at any time with a simple tool. Are there other reasons why you want to replace the crab? If not, then doesn't seem at all worth it.
The carbs have been drilled, but the screw itself is only accesible from the underside of the carb. It's hard to reach with any tool i have to turn the screw, and i have no visual whatsoever of what im doing.
I like to have the screw on the side of the carb, like you see a lot on dirtbikes.
To some degree i gues if it plugs, it plays, but if there are specific recommendations of what carbs i should get, i would like to know sooner rather then later.
Someone mentioned GSXR 36mm carbs earlier somewhere. IIRC they said it's even available in 'pairs' modded to fit the GS.
If you are looking for brand new carbs, look at Mikuni carbs. Aside from the BS carbs (CV carbs with butterfly valves) they make mechanical carbs too (the throttle cable physically lifts the slides). I have VM34'S on my GR650, and they have the mixture screws on the sides.
I do have to warn you though: setting up non-stock carbs to any engine is going to be a LOT more work than reaching your current mixture screws.
Good point from Big Rich. I'm not telling you which way to go here but I think reaching the mixture screw will be a walk in the park by the time you're done finding, replacing, then troubleshooting a new carb.
Over the years I've seen people fashion really creative tools for reaching idle mixture screws. When adjusting it I always close it fully, then increase the number of turns starting at zero.
I know it is a pain but maybe before replacing, search around for creative ways to make it easier for you. Not to mention, I don't how much you paid for the bike, but do you really want to drop $400 on a new setup?
Why not grab some LongBoy screws from Factory Pro? Just dremel one side flat so you have a point of reference. Completely negates the need for a flat head bit.
JAS6377, You da real MVP!
Thats a great idea. I didnt know those even existed. Hell, i should've thought of this myself. Thanks man!
What do you mean by dremeling one side flat?
Everyone else, thanks for helping me figuring things out. but especially for the price, im going to get myself some of those extended screws.
I too strongly recommend doing *anything* other than swapping carbs. Carbs from other bikes will be the least plug-and-play thing in the world!The rejetting will drive you nuts!!
Quote from: Krav on December 18, 2014, 01:29:20 AM
What do you mean by dremeling one side flat?
So you can easily see how many turns you are making.
I was going to suggest some form of braze-on extension for the screws.I didnt know the long accessory screws existed.They're a great idea
After doing research, those screws are going to be a bit of an issue.
First, i would need from 89-00 screws, which they dont make anymore. and if i would order them, i would need to order a batch.
What im going to do now, im going to have a VERY technical colleague drill a hole of 1,9mmin the screw, and press a 2,0mm pianostring in there. then have a 90 degrees bent at the end, and be able to turn the screw that way.
That piano string is supposed to be thusly stiff that it wil never bent in an elastic way, so i think this might work best, and to me is a free solution.
Should be a good mod. Let us know how it goes others may be interested in doing something similar. Luckily I haven't had to reset my screw more than once but I haven't had the bike long. I may be facing the same frustration down the road. Good luck
Ill put it up on my project page, and here when done.
That's an interesting solution,it could be excellent!Looking forward to hearing how it goes
I thought of something similar. but soldering bicycle cable with the sleeves, onto the screw heads. using hard solder. my project page - when I get around to carbs, ill be trying this.
Once the EPA Plug is gone (carbs have to be off for that anyway) you set the screws to 3 turns out and forget about them.
You are trying to create a solution for a problem that doesn't exist.
One of those short tips for a muti tip screwdriver is all you need if you want to adjust the Idle Mixture with the carbs on the bike
Quote from: Krav on December 18, 2014, 05:36:39 AM
After doing research, those screws are going to be a bit of an issue.
First, i would need from 89-00 screws, which they dont make anymore. and if i would order them, i would need to order a batch.
Did they tell you how many constitutes a batch?
Quote from: Suzuki Stevo on December 19, 2014, 09:45:19 AM
Once the EPA Plug is gone (carbs have to be off for that anyway) you set the screws to 3 turns out and forget about them.
You are trying to create a solution for a problem that doesn't exist.
One of those short tips for a muti tip screwdriver is all you need if you want to adjust the Idle Mixture with the carbs on the bike
That is not the correct way to adjust pilot screws. Each carb must be adjusted independently when the engine is hot (running). Screw is adjusted to get the highest idle speed on each carb and then proper idle RPM is adjusted by the idle mechanical stop screw. Fixed setting reference (3 turns) is for getting engine running after carb rebuild or cleaning. Those that cite fixed screw position on the web are wrong. Sorry.
On my ATV's and some of my motorcycles I have purchased "Big Head" fuel mixture screws or remote adjusters like the ones shown on this page:
http://www.motorcycle-superstore.com/motorcycle/Adjustable%20Fuel%20Screw
There may be some for GS
Quote from: dennisgb on December 19, 2014, 02:09:10 PM
Quote from: Suzuki Stevo on December 19, 2014, 09:45:19 AM
Once the EPA Plug is gone (carbs have to be off for that anyway) you set the screws to 3 turns out and forget about them.
You are trying to create a solution for a problem that doesn't exist.
One of those short tips for a muti tip screwdriver is all you need if you want to adjust the Idle Mixture with the carbs on the bike
That is not the correct way to adjust pilot screws. Each carb must be adjusted independently when the engine is hot (running). Screw is adjusted to get the highest idle speed on each carb and then proper idle RPM is adjusted by the idle mechanical stop screw. Fixed setting reference (3 turns) is for getting engine running after carb rebuild or cleaning. Those that cite fixed screw position on the web are wrong. Sorry.
I did that...ended up at 3 where I started, like everyone else here.
EDIT: But I use a manometer when syncing, not a drill bit :thumb:
Quote from: Suzuki Stevo on December 19, 2014, 03:43:30 PM
I did that...ended up at 3 where I started, like everyone else here.
I just don't believe that Steve. Carbs are tuned for the location. They will perform different depending on altitude and a number of different conditions. I've rarely had a multi carb set-up where the carb fuel adjustment was the same between carbs let alone the same between bikes.
Add to that any mods on the bike and what you are saying is just not possible.
This is a bug of mine. This static setting recommendation is all over the web and it is just plain wrong. Other's on the web that don't understand take this information as correct...it's not.
Quote from: dennisgb on December 19, 2014, 05:24:43 PM
Quote from: Suzuki Stevo on December 19, 2014, 03:43:30 PM
I did that...ended up at 3 where I started, like everyone else here.
I just don't believe that Steve. Carbs are tuned for the location. They will perform different depending on altitude and a number of different conditions. I've rarely had a multi carb set-up where the carb fuel adjustment was the same between carbs let alone the same between bikes.
Add to that any mods on the bike and what you are saying is just not possible.
This is a bug of mine. This static setting recommendation is all over the web and it is just plain wrong. Other's on the web that don't understand take this information as correct...it's not.
I have had multiple carbs since 1972, I tried your
correct way, I tried the 25 Rpm lean drop, I even used a vacuum gauge and tried using the highest vacuum to set the mixture screw, but in the end and 25+ bikes down the road I set the mixture screws the way I do because it works....works for me anyway :thumb:
Good for you...it's still not the right way to do it.
https://www.youtube.com/watch?v=zm5mB3R8Ucw
Quote from: Suzuki Stevo on December 19, 2014, 03:43:30 PM
Quote from: dennisgb on December 19, 2014, 02:09:10 PM
Quote from: Suzuki Stevo on December 19, 2014, 09:45:19 AM
Once the EPA Plug is gone (carbs have to be off for that anyway) you set the screws to 3 turns out and forget about them.
You are trying to create a solution for a problem that doesn't exist.
One of those short tips for a muti tip screwdriver is all you need if you want to adjust the Idle Mixture with the carbs on the bike
That is not the correct way to adjust pilot screws. Each carb must be adjusted independently when the engine is hot (running). Screw is adjusted to get the highest idle speed on each carb and then proper idle RPM is adjusted by the idle mechanical stop screw. Fixed setting reference (3 turns) is for getting engine running after carb rebuild or cleaning. Those that cite fixed screw position on the web are wrong. Sorry.
I did that...ended up at 3 where I started, like everyone else here.
EDIT: But I use a manometer when syncing, not a drill bit :thumb:
Oh please.
Once i fitted my podfilters, 3 turns wouldnt run anywhere near good.
Chosing a static setup for a component that deals with LOTS of variables (surrounding air and atmosphere + mods).
please remind me to never have you tune my bike.
I don't want to be rude, but the things you say........ people may think that you say the truth, and i (along with others so it seems) CANNOT agree with the things you are saying.
Quote from: Krav on December 19, 2014, 05:49:57 PMOh please.
Once i fitted my podfilters, 3 turns wouldnt run anywhere near good.
Chosing a static setup for a component that deals with LOTS of variables (surrounding air and atmosphere + mods).
please remind me to never have you tune my bike.
I don't want to be rude, but the things you say........ people may think that you say the truth, and i (along with others so it seems) CANNOT agree with the things you are saying.
You got me...I'm just making this stuff up as I go :wink:
Quote from: Suzuki Stevo on December 19, 2014, 09:45:19 AM
Once the EPA Plug is gone (carbs have to be off for that anyway) you set the screws to 3 turns out and forget about them.
You are trying to create a solution for a problem that doesn't exist.
One of those short tips for a muti tip screwdriver is all you need if you want to adjust the Idle Mixture with the carbs on the bike
Your point in this post was that you can set them at 3 turns out and forget about them.
That is not the proper way to adjust the pilot circuit. Like you said it works for you, and you also likely have no idea if you are running rich or lean at idle...just because you get reasonable throttle response does not mean your carbs are adjusted properly. To make a blanket statement to everyone who might want to adjust their carbs that is wrong is not of benefit to the forum.
This is a direct quote from the Mikuni tuning manual:
"Selection of the opening of the air screw should be made in the following manner. First, warm up the engine adequately and set the throttle stop screw so that the engine revolution at idling will be about 10-20% higher than the number of revolutions you are aiming at. Then, turn the air screw left or right and select the position where the engine revolution reaches maximum. Adjust the throttle stop screw to bring down the engine revolution to your target speed for idling."Who do you want to believe? It is not me arguing with you...it is fact that this is how to properly adjust the pilot circuit. Why do you think the OP was asking how to make this adjustment easier?
Quote from: dennisgb on December 19, 2014, 06:05:54 PM
Quote from: Suzuki Stevo on December 19, 2014, 09:45:19 AM
Once the EPA Plug is gone (carbs have to be off for that anyway) you set the screws to 3 turns out and forget about them.
You are trying to create a solution for a problem that doesn't exist.
One of those short tips for a muti tip screwdriver is all you need if you want to adjust the Idle Mixture with the carbs on the bike
Your point in this post was that you can set them at 3 turns out and forget about them.
That is not the proper way to adjust the pilot circuit. Like you said it works for you, and you also likely have no idea if you are running rich or lean at idle...just because you get reasonable throttle response does not mean your carbs are adjusted properly. To make a blanket statement to everyone who might want to adjust their carbs that is wrong is not of benefit to the forum.
This is a direct quote from the Mikuni tuning manual:
"Selection of the opening of the air screw should be made in the following manner. First, warm up the engine adeqquately and set the throttle stop screw so that the engine revolution at idling will be about 10-20% higher than the number of revolutions you are aiming at. Then, turn the air screw left or right and select the position where the engine revolution reaches maximum. Adjust the throttle stop screw to bring down the engine revolution to your target speed for idling."
Who do you want to believe? It is not me arguing with you...it is fact that this is how to properly adjust the pilot circuit. Why do you think the OP was asking how to make this adjustment easier?
A wise man knows when to put the book down and when to pay attention to it....
Quote from: Suzuki Stevo on December 19, 2014, 06:15:39 PM
A wise man knows when to put the book down and when to pay attention to it....
A wiser man knows when to admit he is wrong.
So you are smarter than the manufacturer :o
Those reading this please follow the proper procedure and do not listen to the "Wise Man".
Quote from: dennisgb on December 19, 2014, 06:30:33 PM
Quote from: Suzuki Stevo on December 19, 2014, 06:15:39 PM
A wise man knows when to put the book down and when to pay attention to it....
A wiser man knows when to admit he is wrong.
So you are smarter than the manufacturer :o
Those reading this please follow the proper procedure and do not listen to the "Wise Man".
You seem to be preoccupied with the assumption there is only one way to do something and somebody has to be right and somebody has to be wrong :dunno_black:
Quote from: Suzuki Stevo on December 19, 2014, 06:38:11 PM
You seem to be preoccupied with the assumption there is only one way to do something and somebody has to be right and somebody has to be wrong :dunno_black:
The Mikuni manual is clear. That is the "right" way to adjust the pilot circuit.
You seem to be preoccupied with arguing until the death...because you are incapable of accepting that you are wrong.
Stick an O2 sensor up your pipe and measure the mixture ratio at idle and report back.
I do that with every bike I tune and I've never had multiple bikes set at 3 turns out...ever.
In fact once you get to three turns it is recommended that you change your pilot jet(s).
But someone with as much experience and knowledge as you should know that. ;)
"Selection of the opening of the air screw should be made in the following manner. First, warm up the engine adeqquately and set the throttle stop screw so that the engine revolution at idling will be about 10-20% higher than the number of revolutions you are aiming at. Then, turn the air screw left or right and select the position where the engine revolution reaches maximum. Adjust the throttle stop screw to bring down the engine revolution to your target speed for idling."
That's the way I learned to do it 67 years ago when I went to work in a garage on cars at age 15. But times have changed. I've never seen the need to adjust the idle mix on the 6 motorcycles I rode 400k+ miles over the last 30 years. Don't even know what the idle mix screws look like on a bike, they're hidden behind plugs. :icon_lol: Those reading this please follow the proper procedure and leave those plugs where they belong. :thumb:
"Don't mess with your carbs and they won't mess with you."
Back to the original question.
Krav,
I did a little searching and I think there are "Big Head" pilot screws that will work for the GS500.
This one is recommended for Mikuni carbs...
Factory Pro "Long Boy" 5020m
Another approach would be to modify your existing pilot screws like this:
(http://i1033.photobucket.com/albums/a414/dennisgb1/Image1_zps63490492.jpg) (http://s1033.photobucket.com/user/dennisgb1/media/Image1_zps63490492.jpg.html)
Quote from: gsJack on December 19, 2014, 06:53:40 PM
That's the way I learned to do it 67 years ago when I went to work in a garage on cars at age 15. But times have changed. I've never seen the need to adjust the idle mix on the 6 motorcycles I rode 400k+ miles over the last 30 years. Don't even know what the idle mix screws look like on a bike, they're hidden behind plugs. :icon_lol: Those reading this please follow the proper procedure and leave those plugs where they belong. :thumb:
"Don't mess with your carbs and they won't mess with you."
The problem is when the carbs get dirty and you need to clean the pilot jet, which is the first thing to plug up...you need to take the screw and the jet out to clean it/them.
Also if you re-jet your carb(s).
It is necessary to adjust them. You've been lucky...
Ya, must all be just luck. :icon_lol:
I love it when children argue with their elders... but of course that has nothing to do with what's happening here....
Regardless, I have those Factory Pro screws (or something nearly identical) on my GS.
I haven't gotten to the point where I need to see if they work (tank is still off), but they do look like they'll make the adjustment easier, if needed.
At the moment, they are set a +3 turns out, as suggested by nearly every highly experienced GS tuner on this board, and every other place I've found online.
Quote from: gsJack on December 19, 2014, 07:38:44 PM
Ya, must all be just luck. :icon_lol:
Jack,
Where are you at? Here in the Midwest of the USA the fuel quality is so bad due to ethanol content that it can and does plug up the fuel circuits in the carbs. It's a pretty common problem where I am because the bikes sit for 6 months out of the year (Minnesota). I run my carbs out and stabilize my fuel so have less of a problem but it is pretty common. On some of my bikes I only run premium without ethanol, but it's hard to find.
Ethanol creates organic growth in the fuel if it sits...in carbs it gums them up and makes a mess. Pilot jets are tiny and are the first to plug up.
Dennis
Quote from: Elmojo on December 19, 2014, 07:52:42 PM
I love it when children argue with their elders... but of course that has nothing to do with what's happening here....
Regardless, I have those Factory Pro screws (or something nearly identical) on my GS.
I haven't gotten to the point where I need to see if they work (tank is still off), but they do look like they'll make the adjustment easier, if needed.
At the moment, they are set a +3 turns out, as suggested by nearly every highly experienced GS tuner on this board, and every other place I've found online.
Well I guess there are a bunch of people who just want to argue...and don't care what the manufacturer's say.
My question is why did you put "Factory Pro" adjustable screws on if you intend to run them at a static setting you read on line?
That makes absolutely no sense.
There isn't a competent tuner in the world that wouldn't tell you 3+ turns means you need to resize your jets...you are getting to the end of the travel and the spring will not have enough tension to hold the screw in the carb...good luck with that.
Amazing bunch of hogwash on this forum tonight.
Quote from: dennisgb on December 19, 2014, 08:10:01 PMWell I guess there are a bunch of people who just want to argue...and don't care what the manufacturer's say.
My question is why did you put "Factory Pro" adjustable screws on if you intend to run them at a static setting you read on line?
That makes absolutely no sense.
There isn't a competent tuner in the world that wouldn't tell you 3+ turns means you need to resize your jets...you are getting to the end of the travel and the spring will not have enough tension to hold the screw in the carb...good luck with that.
Amazing bunch of hogwash on this forum tonight.
So anybody that disagrees with you is arguing?
Your not disagreeing with me.
Those of you preaching this screwed up static method are disagreeing with the manufacturer's recommended methods and anyone who actually knows how to tune carburetors.
That is an argument that you are continuing trying to prove you are right.
Your not. Go to the Mikuni website and read the tech data.
http://www.mikuni.com/
http://www.mikuni.com/pdf/vmmanual.pdf
http://www.motorcyclecarbs.com/carbs101.pdf
Flapping your gums without any substantiation for your claims is arguing for the sake of argument.
You can't admit you are wrong and continue to claim you are right.
You have shown nothing but so and so said this so it's right, or this is how I do it so it's right.
The GS guys said this is how you do it.
It's not right.
Suzuki Stevo you sir are now on my ignore list.
Quote from: dennisgb on December 19, 2014, 09:38:00 PM
Your not disagreeing with me.
Those of you preaching this screwed up static method are disagreeing with the manufacturer's recommended methods and anyone who actually knows how to tune carburetors.
That is an argument that you are continuing trying to prove you are right.
Your not. Go to the Mikuni website and read the tech data.
http://www.mikuni.com/
Go to a decent tuning website and actually read the information:
http://www.dansmc.com/carbs2.htm
Flapping your gums without any substantiation for your claims is arguing for the sake of argument.
You can't admit you are wrong and continue to claim you are right.
You have shown nothing but so and so said this so it's right, or this is how I do it so it's right.
The GS guys said this is how you do it.
It's not right.
Dude...my house has been paid for for 15 years, a big chunk of what paid for it is from spinning wrenches at a professional and hobby level, I don't care what the book says, you are so phuking hung up on proving yourself right....do me a favor, get over yourself. You basically are just saying "I'm Right, I'm Right, I'm Right, the book says so...your wrong!". I have made allot of money doing it wrong for years :flipoff:
Stevo,
I've been building and racing cars and motorcycles for 45 years...I have multiple national trophy winners. Customs, classics, you name it. Worked professionally as a mechanic and then went into engineering. Worked in the pits as a mechanic for a national race team. You wrenching in your garage is great but I wouldn't let you touch anything of mine because you have proven here you know nothing. Your all talk. You have shown nothing to substantiate your claim that your method is how it "should" be done, but you continue to spew it out on the web. I have shown the manufacturer's method which is how I explained it originally. For those that know the proper way to tune a carburetor, you have shown how little you know and made a fool of yourself. Good luck with your wrenching.
You have also done nothing to help the original poster...just mucked up his thread with your crap.
Quote from: dennisgb on December 19, 2014, 10:22:19 PM
You have also done nothing to help the original poster...just mucked up his thread with your crap.
Backup the truck Buckwheat..I thought I was on your Ignore List?
And your wrong..I posted mostly sentences while you where dropping paragraphs in every post, so actually you mucked it up more. Oh yeah I forgot, your right and I'm wrong so in your mind I mucked it up more :icon_sad:
Let me also quote myself from the first page the most honest statement I could make on the subject (minus the part you can't let go)
Quote from: Suzuki Stevo on December 19, 2014, 09:45:19 AM
You are trying to create a solution for a problem that doesn't exist.
One of those short tips for a muti tip screwdriver is all you need if you want to adjust the Idle Mixture with the carbs on the bike
Quote from: dennisgb on December 19, 2014, 10:16:47 PM
Stevo,
I've been building and racing cars and motorcycles for 45 years...I have multiple national trophy winners. Customs, classics, you name it. Worked professionally as a mechanic and then went into engineering. Worked in the pits as a mechanic for a national race team. You wrenching in your garage is great but I wouldn't let you touch anything of mine because you have proven here you know nothing. Your all talk. You have shown nothing to substantiate your claim that your method is how it "should" be done, but you continue to spew it out on the web. I have shown the manufacturer's method which is how I explained it originally. For those that know the proper way to tune a carburetor, you have shown how little you know and made a fool of yourself. Good luck with your wrenching.
Congratulations, you made it farther than I ever did wrenching...now if you will just pull your head out of your arse and stop trying to prove yourself right :cheers:
EDIT: Ok I quit, as long as somebody else quits :icon_rolleyes:
But I also know you have to get the last word in, so make it good, my work is done here/
And never forget: the GS is not rocket science, it's more like tractor science.
Does seem to me though that the carbs are assembled with the idle screws set at a certain number of turns and then plugged before they are installed on the engines at the factory? Doubt they adjust them like Mikuni says hot and running after assembly.
Is it possible that in many cases BOTH sides end up correct?
That is, at roughly 1 ATM pressure (so, reasonable altitude near sea level, not the Andes), with non-EtOH fuel of average developed-world quality, a decent air filter of OEM quality, and no leaks, that both Mikuni book followers and 3-turns followers will end up close?
Quote from: dennisgb on December 19, 2014, 06:42:54 PM
Him -The Mikuni manual is clear. That is the "right" way to adjust the pilot circuit-
You -Stick an O2 sensor up your pipe and measure the mixture ratio at idle and report back.
I can easily imagine a situation where Mikuni might quote an imperfect procedure- even if only for simplicity's sake.And also because their procedure get's it 'near enough to perfect'.
So dont be surprised if we laugh at both of you (but mostly him) ;-)
Quote from: Rallyfan on December 19, 2014, 11:49:46 PM
Is it possible that in many cases BOTH sides end up correct?
That is, at roughly 1 ATM pressure (so, reasonable altitude near sea level, not the Andes), with non-EtOH fuel of average developed-world quality, a decent air filter of OEM quality, and no leaks, that both Mikuni book followers and 3-turns followers will end up close?
Every ride I go on over an hour takes me from Sea level over one of Washington's many Mountain Passes, so I never got hung up on trying to make it perfect, all my bikes are EFI now anyway. It's kinda like an oil thread...do what gives you the most piece of mind. :dunno_black:
Fair enough. I do envy EFI but that's another story.
Quote from: Rallyfan on December 19, 2014, 11:49:46 PM
Is it possible that in many cases BOTH sides end up correct?
That is, at roughly 1 ATM pressure (so, reasonable altitude near sea level, not the Andes), with non-EtOH fuel of average developed-world quality, a decent air filter of OEM quality, and no leaks, that both Mikuni book followers and 3-turns followers will end up close?
3 turns out is close to the end of travel. Most tuner's understand that about 2 is optimum. This is measured by how the engine runs after tuning or rejet. Most bikes in the USA are set lean from the factory to meet EPA emissions. One size up on jet size usually improves running without any other mods. If your at 3 turns and are using the RPM method for tuning you could consider changing jet size but it's probably ok.
If you are at 3 turns and just set them like this because you read it on the web, ask yourself the following questions:
1). Do I know if I'm running rich or lean?
2). What are the consequences of running rich or lean? Can it damage the bike?
3). Do I have optimum throttle response? Do I know the difference?
Altitude and weather, temp and many other conditions in your particular area also effect how your engine runs. How can one setting fit all situations? Fuel type and additives also have an effect.
The reason that the book takes you through running "your" engine is to insure that the fuel mixture is set properly for your bike, where you are, with the fuel you are running.
Yes you guys are right...it's not rocket science, but it also isn't plug and play.
Krav,
Regardless of what method you use to set your mixture screws...you do understand it's something you only need to do ONCE in a motorcycles life, if at all?
You are over thinking the whole process of turning a screw, it's not hard to access and adjust the mixture screws once the plugs are gone, take a screwdriver tip as I have mentioned before, add a bit of fuel line to it for a handle, leave it in the watch pocket of your pants...that way you will have it around and you can wank with your mixture screws every ride if you want?
The one in this photo is over 40 years old, it's really all you need even if you feel the need to tweak the mixture screws daily.
(http://home.comcast.net/~stykers/mixscrew.jpg)
Can I stick my oar in :D
When carbs are made in the factory they are set up and adjusted on rigs, the manufacturers use an inert gas, vacuum pumps, flow meters and analyser's to check the delivery rates and mixture strengths. It takes seconds then the plugs go in. The bike manufacturers state these figures and they are a compromise between economy. performance fuel strengths and emission legislation. The idea is they work straight out of the box and can go straight on the bike while its on the line without wasting any time making major adjustments..
If its some highly tuned race engine or if you are obsessed with getting another 0.001hp out of it there may be a case to answer in fiddling with the carb settings n conjunction with other work but otherwise leave well alone, you are not going to see any measurable improvement.
Dennis?.....what you say holds some substance but to apply it on a GS5 with an average rider.....nah........total overkill. If adjusting the pilots was a necessity......they wouldn't be blanked off and to be brutally honest, missing pilot plugs are a major turn off to any potential (and clued up) buyer.
Quote from: sledge on December 20, 2014, 08:51:36 AM
Dennis?.....what you say holds some substance but to apply it on a GS5 with an average rider.....nah........total overkill. If adjusting the pilots was a necessity......they wouldn't be blanked off and to be brutally honest, missing pilot plugs are a major turn off to any potential (and clued up) buyer.
I'm beginning to understand that. Tuning is a difficult subject to discuss...understanding that the pilot screw position tells you if your pilot jet size is right is a little beyond the average user. The question I have is how can you clean your dirty carbs if you don't take the pilot screw and jet out? So you have to break the cap the first time you clean your carbs...and then you have to set them after you put them together.
Will a static setting work? Probably. Is it optimum? Highly unlikely. So if you hear that funny popping sound, or a slight backfire when backing down...you should be aware that you can fix that. Or when you hit the overlap at 1/8 throttle and there is a little hesitation, maybe if you adjusted those screws you could get rid of that.
Only a very few buyers are savy enough to look at the bottom of the carbs to see if the factory screw caps are on there.
I just viewed a video a buddy sent me of his bike on his dyno, showing the fuel mapping software going through it's paces...it's sort of funny talking about something as simple as a pilot screw and getting nothing but flack.
Good luck to all you guys. I've decided to leave this forum. Not worth the effort.
Quote from: dennisgb on December 20, 2014, 09:16:00 AMGood luck to all you guys. I've decided to leave this forum. Not worth the effort.
Dennis,
Let me be the first to say..don't just take your ball and go home, you obviously have decades of experience, your only flaw is your incessant tunnel vision in thinking there is only one way to skin a cat, please stay and share your knowledge :cheers:
I'd hate to see you go, too, Dennis. I don't know enough about this topic to chime in....but I've learned a lot from the spirited debate.
Roaring via Tapatalk.
Only a very few buyers are savy enough to look at the bottom of the carbs to see if the factory screw caps are on there.
That's correct.....but they are around, as I have just demonstrated :thumb:
Regarding cleaning, I have had satisfactory results without touching the pilot screw, after all it only governs air flow and doesn't', or shouldn't!! see any fuel.
A missing plug wouldn't put me off buying a GS5, but I would be aware that it may put someone else off and it does indicate that someone has been at the carbs and you then have to ask what was that person doing and more importantly did they KNOW what they are doing.
Cant see why you feel you have to leave.....Its not a contest and you are under no obligation to say anything, people will either take your advice on board and believe what you say or they wont, no sense in getting upset if they don't. The mistake a lot of people in here make is paying more attention to who is doing the talking rather than what's being said......frustrating sometimes but just let it ride, its not your loss.
I'm going to give this one more shot.
This is not an argument...I have been trying to present the methods used by every motorcycle tuner that I know...along with manufacturer recommendations, and most of the rest of the web.
There are two different types of pilot fuel/air delivery systems. There are pilot screws that adjust the amount of fuel being delivered and pilot screws that adjust the amount of air being delivered to the pilot jet outlet.
In either case the fuel and air must be mixed and delivered to the throat of the carburetor. The pilot jet pulls fuel from the float bowl which is mixed with the air coming from the air screw chamber at the tip of the air screw. The air and fuel are connected together. This means that fuel can get into the air delivery chambers and thus can plug the air screw and or the chambers or both. It is common practice to remove the pilot air or fuel screw, spring, washer and o-ring during cleaning and rebuilding. The o-rings degrade over time and should be inspected and replaced. Damaged o-rings will allow air or fuel to escape past them and thus make it difficult to adjust the mixture.
When cleaning and rebuilding carburetors parts should not be left installed during cleaning. The small air and fuel passages can plug with dirt from the cleaning process if there is no place for dirt and debri to go (the mixture screws left in act as plugs if not removed). The openings in the pilot jets and air openings are very small .025"-.040" and get plugged very easily particularly when the engine is only run occasionally. Carb cleaners and compressed air generally do not work to clean these small orifices. Small wire probes are generally used to clear these small orifices. Care must be taken to not damage these openings.
It is very rare not to find some dirt, sludge, varnish or other debri in a carburetor that has miles on it and has not been opened for a while. Sometimes just sitting for a month with fuel in the carb will plug it up. Fuel sitting in the float bowl can find it's way into the air junction at the pilot jet. Many fuels today contain ethanol which will produce organic growth in a little as a month of sitting in a carburetor. Poor idling, popping and backfiring are symptoms of a dirty pilot circuit. These also can be symptoms of an improperly adjusted pilot circuit.
Hesitation during the crossover from the pilot circuit to intermediate or main circuit at approximately 1/8 throttle is also a symptom of a dirty or improperly adjusted pilot circuit.
Information on proper adjustment of carburetor pilot circuits is available all over the web. There is a misunderstanding between manual recommended static settings for "Start-Up" after rebuilding or cleaning carburetors. People all over the web have construed this information as the "Recommended" settings. It is not. This is a simple statement of fact. The recommended setting is in order to get the engine running. Once warm the RPM method is recommended by every motorcycle manufacturer as well as the carburetor manufacturer's for setting the pilot circuit.
Manufacturer's were forced to cap the pilot screws in order to meet the requirements of the EPA. The factory setting is different depending on where the bike will be sold. I know this because I bought a CBR California bike and it would not run in Minnesota. The main problem with capped pilot screws is the bike will eventually need to be tuned or need the carbs cleaned or rebuilt. So those that keep citing the fact that the pilot screws are capped from the factory so it makes no difference need to consider this was a compromise and in fact every motorcycle sold is set too lean from the factory and thus is not running at optimum.
Now, those that have said they never had to worry about taking the pilot screw out must be living in the cleanest place in the world with perfect fuel, because I have never taken a carb apart that didn't need to be cleaned.
I wonder if this carb needs to be cleaned? Do you think the pilot circuit "could" be dirty?
(http://i1033.photobucket.com/albums/a414/dennisgb1/dirtycarb_zpsf61966f3.jpg) (http://s1033.photobucket.com/user/dennisgb1/media/dirtycarb_zpsf61966f3.jpg.html)
Sure this is an extreme case, but I have seen that black goop in a lot of carburetors.
Usually they look something like this:
(http://i1033.photobucket.com/albums/a414/dennisgb1/anotherdirtycarb_zps7d41bf0f.jpg) (http://s1033.photobucket.com/user/dennisgb1/media/anotherdirtycarb_zps7d41bf0f.jpg.html)
This isn't about forcing some pro tuning method. It's really is the method that is in most every shop manual.
This is an excerpt direct from my CBR manual:
(http://i1033.photobucket.com/albums/a414/dennisgb1/CBRManualEcerpt_zps7bf61486.jpg) (http://s1033.photobucket.com/user/dennisgb1/media/CBRManualEcerpt_zps7bf61486.jpg.html)
And Honda Shadow 750
(http://i1033.photobucket.com/albums/a414/dennisgb1/HondaShadowExcerpt_zpsf4246472.jpg) (http://s1033.photobucket.com/user/dennisgb1/media/HondaShadowExcerpt_zpsf4246472.jpg.html)
Norton
(http://i1033.photobucket.com/albums/a414/dennisgb1/NortonExcerpt_zpsb3537869.jpg) (http://s1033.photobucket.com/user/dennisgb1/media/NortonExcerpt_zpsb3537869.jpg.html)
These are manuals I have for my bikes, but you could go into any manual and find a similar description on how to do this.
It is the method that is used by everyone...except GS500 owners on the GSTwin Forum.
Far out. .. I missed this thread till now! ... I like gsJack quote the best. .. 'don't mess with your carbs and they won't mess with you' , or something like that. ...
The rest is just a slide rule pissing match.... sure the things can be tweaked to the n'th degree. .. for frag all power gains... but in the mind of the tweakers is the satisfaction of rightness....
The rest of we Muppets just leave shaZam! alone and ride along happily mostly...
I might have to check my bike though. .. it's had e10 sitting in its tank for a few months at a time quite often this year. .. it starts and runs fine every time too. ... MUST be something wrong with it eh! ...
Now excuse me while I finish chuckling after re reading some of the posts. ... I do love a experts pissing match!
Quote from: dennisgb on December 20, 2014, 08:14:19 PMThe factory setting is different depending on where the bike will be sold. I know this because I bought a CBR California bike and it would not run in Minnesota.
I am getting this image in my mind............Dennis speeding towards the state line on his CBR then wondering why it suddenly spluttered to a halt the instant he crossed it because the pilot screws needed another 1/2 turn
:D :D :D
Maybe they should be putting up signs.....
----------------------------------------------
XX WARNING XX
You are now entering Minnesota
Adjust your pilot jets accordingly
Have a nice day
----------------------------------------------
If I was riding my KZ1000 down the road and it came to my attention that the idle mixture screw on the #3 cylinder was set to 1.3/4 turns out and wasn't set to 2 turns out like the other 3 cylinders :mad:
I would pull over to the side of the road, break out the screwdriver from the kit and set it to 2 turns out so it matched the other 3 carbs, but that scenario would never have happened because on every 4 cylinder bike I have ever owned, once I get all 4 idle mixture screws set to the exact same *number of turns out I put a drop of paint on the screw so I never have to worry about adjusting the idle mixture screws ever again, whenever I deal with multiple anything, consistency is key to me..right or wrong I have always done it that way.
*A number where the bike starts good, idles smooth and transitions when the grip is twisted without hesitation.
Dennis?
I noticed the comment below you made.
"I have been trying to present the methods used by every motorcycle tuner that I know...along with manufacturer recommendations, and most of the rest of the web"
Just about all the `serious` techs I know use exhaust gas analysers and base the idle adjustment on the CO content in the exhaust rather than the actual physical position of the adjustment screw. What are your comments on this method?
Times have changed, nowadays I just take my EFI bikes to my tuner Nels at 2 Wheel DynoWorks and have him strap the bikes down on his chassis dyno, hookup his laptop and tweak the fuel maps, all I have to do now is maintenance, add fuel and ride them, to hell with idle mixture screws :thumb:
(http://home.comcast.net/~stykers/dyno01.jpg)
GSX650F
(http://home.comcast.net/~stykers/gsxdyno.jpg)
(http://home.comcast.net/~stykers/dynodl02.jpg)
V-Strom 650
(http://home.comcast.net/~stykers/dynodl.jpg)
:o :o :o :o :o :o :o :o :o
Quote from: dennisgb on December 19, 2014, 06:42:54 PM
The Mikuni manual is clear. That is the "right" way to adjust the pilot circuit.
You seem to be preoccupied with arguing until the death...because you are incapable of accepting that you are wrong.
Stick an O2 sensor up your pipe and measure the mixture ratio at idle and report back.
I do that with every bike I tune and I've never had multiple bikes set at 3 turns out...ever.
In fact once you get to three turns it is recommended that you change your pilot jet(s).
But someone with as much experience and knowledge as you should know that. ;)
Sledge,
Maybe you should actually follow the thread instead of trying to look like you know what your talking about.
You people are argumentative and nasty.
I have better things to do.
Good luck.
Geez Dennis...I am not disputing anything, carb tuning is not something I consider myself to be particularly knowledgeable and I don't generally comment on the topic all I did was ask for your opinion and comments :dunno_black:
And you say its us who are argumentative and nasty........oh the irony :D
Maybe you would be better off in another forum............... this one obviously doesn't revolve around you and that's what seems to be the real problem here :thumb:
A rare moment of agreement here! ;)
So I grab some coffee, take the dog for a walk, come back and the frigging ball is gone again :icon_sad:
There was a ball? :confused:
As in....
Quote from: Suzuki Stevo on December 20, 2014, 09:28:02 AM
Dennis,
Let me be the first to say..don't just take your ball and go home, you obviously have decades of experience, your only flaw is your incessant tunnel vision in thinking there is only one way to skin a cat, please stay and share your knowledge :cheers:
http://www.urbandictionary.com/define.php?term=I%27m%20going%20to%20take%20my%20ball%20and%20go%20home! (http://www.urbandictionary.com/define.php?term=I%27m%20going%20to%20take%20my%20ball%20and%20go%20home!)
"The expression comes from the playground where one kid, the one who owns the soccer ball or basket ball, doesn't get his way in the game. If he doesn't get his way then he gets mad and punishes those who are unwilling to accept his mandate. He does this my taking his ball and going home thus ending the game and any fun the participants were having.
The expression "I'm going to take my ball and go home" when directed at an individual is used to illustrate the individual's immaturity when that person can't get his way and no longer wants to be a participant in the conversation or a contributor to solving a problem."
Holehmoleh. this has become quite the threat.
What i just wanted to say about the screwdriverbits, is that i can't see and hardly feel if the bit actually caught the screw, or not.
I want an easier way.
Quote from: Krav on December 22, 2014, 01:48:12 AM
Holehmoleh. this has become quite the threat.
What i just wanted to say about the screwdriverbits, is that i can't see and hardly feel if the bit actually caught the screw, or not.
I want an easier way.
The needle with the angle is probably the easiest to work with even with gloves on.
It's the interwebz..serious chit Brah O0
Quote from: Krav on
Today at 03:48:12 AM (http://gstwins.com/gsboard/index.php?topic=68337.msg822211#msg822211)
QuoteHolehmoleh. this has become quite the threat.
What i just wanted to say about the screwdriverbits, is that i can't see and hardly feel if the bit actually caught the screw, or not.
I want an easier way.
The extended screws on mine seem to be about as easy as it gets.
Mine hang down far enough that I mistook them for separate idle adjustments at first, until I looked deeper and saw the real idle adjuster.
I wish I could tell you what brand they are or where they came from, but they were on the bike when I got it.
I can take a photo if it will help.
Ahh. . That ball. .. I must have skimmed past that bit on tapatalk
This thread -despite it's unfortunate little argument- inspired me to retune my pilot screws.
I simply cut a small screwdriver to size and had zero access issues (except it's kinda hot in there :-0 ).
The tuning was slightly fiddly because there is a delay between turning the screws and the revs changing.It's running slightly smoother and more stable now.
FWIW it's at 3.5 turns out now.Does that imply anything about the needle jets? i.e they are slightly too small? I saw someone mention something like that in this thread
3.5 turns? :o
Don't tell Dennis......his head might explode :icon_eek:
Quote from: Ron888 on December 23, 2014, 10:22:04 PM
This thread -despite it's unfortunate little argument- inspired me to retune my pilot screws.
I simply cut a small screwdriver to size and had zero access issues (except it's kinda hot in there :-0 ).
The tuning was slightly fiddly because there is a delay between turning the screws and the revs changing.It's running slightly smoother and more stable now.
FWIW it's at 3.5 turns out now.Does that imply anything about the needle jets? i.e they are slightly too small? I saw someone mention something like that in this thread
You might want to reread the unfortunate part again..Dennis mentioned 3 turns 5 times in our discussion, and by me quoting him the info was repeated another 4 times.
There are 9 references to 3 turns in this thread , are you crazy man....9 references to 3 turns and you end up at 3.5, when Dennis wakes up in the morning there is going to be hell to pay, I wouldn't want to be you :mad:
No, doesn't make my head explode. It just means that the pilot jet is too small. If they are stock it's not a surprise. The experts recommend that you go to the next size pilot jet. You can run it like that if you want.
So the way I read that is......
You can either a) Wind the screw in and take the pilot jet up a size.......or b) Leave it as it is
dunno_black:
Usually recommended that the pilot be changed a size when you get to 3 turns out or 1 turn in. It's how you tell if your pilot is sized right when you don't have an O2 sniffer.
If you are running at 3.5 turns you can leave it like that but it's not recommended because the screw can loosen and fall out.
Also on the far ends of adjustment you don't have the best control over the mix. Particularly when you are almost closed...not my rule...just what is recommended.
I know you guys don't believe anything related to pilot screw adjustment with the exception that a static setting is correct.
It's all cool dude...just don't listen to me and do what you want. When your screws fall out and your bike runs like crap, spend a month on here asking people what's wrong :D
Deleted
Deleted...not worth the effort
Dennis...after about my 6th time putting a screwdriver on the mixture screws of 4 cylinder bike that had never been touch since it left the dealer, only to find all of the screws within a 1/16th of a turn of each other, I came to the conclusion there was really No real advantage to doing it any other way than I do it to this day. My riding lawn mower (single cylinder) is the only rig I adjust as you recommend. I have also been aware of the procedure you posted (numerous times) since I was in Jr High. Please don't implode knowing somebody does something different than the way you do. Respect is earned..you seem to be demanding it?
The 3 turn overlap from the mixture screws to the pilot is correct, my issue is you dogging the static method
It's the interwebz..serious chit Brah, but I think I have said about all I can without repeating myself
Stevo
(http://www.animated-gifs.eu/christmas-merry/0253.gif)
Stevo,
Just do it your way and I'll do it mine and we will all have a nice Holiday :D
You don't have to prove anything an neither do I. You are the ones that are bent out of shape because I won't agree with you.
We disagree...let it rest.
I just commented on the head exploding post and you guys want to start it all up again.
Seriously...I posted what I know and how I do it...you guys have your way...it's all okay.
Hope everyone is safe and happy over the holidays.
Dennis
If the making screws idea falls through, a miniature screwdriver works as well
The way to resolve this really is simple and I'm dismayed plans are not already in place: the proponents of each method tune their bike with that method. They meet in Death Valley and ride to Pike's Peak. I'll wait here because I'm comfortable. Whoever responds to the thread has presumably been correct, as the other will have been left on the side of the road somewhere between CA and CO.
Merry Xmas to all!
Quote from: Rallyfan on December 24, 2014, 11:56:56 AM
The way to resolve this really is simple and I'm dismayed plans are not already in place: the proponents of each method tune their bike with that method. They meet in Death Valley and ride to Pike's Peak. I'll wait here because I'm comfortable. Whoever responds to the thread has presumably been correct, as the other will have been left on the side of the road somewhere between CA and CO.
Merry Xmas to all!
:D
Merry christmas rally and all. That sir was the perfect reply lol. Reminds me of an exasperated parent. But it fits lol
Quote from: Rallyfan on December 24, 2014, 11:56:56 AM
The way to resolve this really is simple and I'm dismayed plans are not already in place: the proponents of each method tune their bike with that method. They meet in Death Valley and ride to Pike's Peak. I'll wait here because I'm comfortable. Whoever responds to the thread has presumably been correct, as the other will have been left on the side of the road somewhere between CA and CO.
Merry Xmas to all!
(http://dsbo73qgdzp2w.cloudfront.net/files/styles/photo/public/gallery/42263/team-jacob-vs-team-edward.jpg)
Quote from: Krav on December 22, 2014, 01:48:12 AMWhat i just wanted to say about the screwdriverbits, is that i can't see and hardly feel if the bit actually caught the screw, or not.
I want an easier way.
First off, Merry X-Mas everyone!
I just had a Brain Fart, maybe find a short piece of fuel/vac line or even maybe some Tygon tubing, that has enough of an interference fit to stay in place when put inside the boss on the carburetors where the brass plug use to be :dunno_black:
Maybe by shrinking the diameter of the hole...that would make it easier to guide a short screwdriver onto the slot of the mixture screw when the carbs are on the bike???
(http://home.comcast.net/~stykers/drill.jpg)
i've been gone for a while... and i missed a gud pissing contest.... damit..... Slegde... you could have invited me to the party.....
why is the tard posting links to tune VM carbs when these are CV type carbs and i can't find shaZam! on tuning BST33 carbs... on the mikuni site.
i do believe the idea of turning the air screws out to 3 is that the gs borg are a bunch of cheap bastards and they try to tweak the carbs to run better instead of actually changing the pilot jets.
other items to consider are....
the pilot ckt is dominant below 1/4 throttle...... so almost never considered while racing.
the GS is a crappy race bike but a gud race bike for the $.... and yes i raced one for 8 YRS
if you are trying to squeak 75+ hp you'd have round slides or flat slides installed.
and
most importantly
this is still a budget bike with budget carbs built to pretty high standards.... therefore the close enuff for a friggin street bike rule still applies.
from what i read the OP added pods and 3 turns out(on pg 2)(i am not going to search elsewhere to see if he/she did something else)
and it runs like crap.... therefore.... fix the problem... bigger pilots???? cause you are at the max of the tweak for that sized pilot.
have you done a plug chop?.... what do the plugs tell you.....
carbs are majical things and FI came out in the 50s and it took them engineers 50-55 yrs to get it to work worth a shaZam!.....
VM, CV, BST...fuel screw or air screw it's all the same. Your tuning the pilot circuit...one goes one way the other goes the other...but heck you guys can split hairs and piss and play forever. I figured that out. Someone put the "smart" hat on you all. Ha! ShaZam! Such a cool phrase man...and I'm the tard. :D
well when i read the pilot tuning of the carb theory.... the numbers are different.... tuning is tuning.... there seems to be no performance tuning specs for the BST carbs.... because it is not a performance carb. i'm glad you are smarter than the borg. but a gs is not an indy car.
welcome to the gs board. you may be more correct than others but most are toooo lazy to perform the perfect tune.... but they are willing to get their bike running better than it did yesterday. therefore close enuff is the general rule. if you research the different types of jet kits avail. they all make the bike run better..but do it differently. jet sizes differ and needle taper differs between them... but they all work.
there seems to be no performance tuning specs for the BST carbs.... because it is not a performance carb.
Your right about that, but the reason isn't performance related. The BST is a model specific carb. Mikuni expects the motorcycle manufacturer to support them...Suzuki decided to not do a very good job of support. I've seen this over and over with carbs that were designed for the specific bikes...it's a pain, but there is info out there. VM's are open market carbs. They are used everywhere. That's why there is a ton of info.
I just put a TM Flat Slide on my Norton and jet sizes, needle info was non-existent. Had to figure it out myself...and that's an open market carb.
As far as needle taper, jet sizes, there are charts to determine what to use...thousands of different combinations...but you can do testing to determine what is right. I shy away from jet kits because they usually contain aftermarket jets and needles which can be problematic. I know that is way beyond what the average rider cares about...part of the reason this thread went south.
I'm concerned whether my bike is running rich or lean...or if it could run better. I use proper tools (O2 sensors are so cheap now anyone can own one) and use the info to tune the best I can. Plug chops are difficult to do with the fuels we have today. They burn much cleaner and it's hard to tell if you are running lean or not. Most people don't understand how to do a proper plug chop.
But like you said this is way more than most people want to do.
Thanks for being cool about it and welcoming me...sorry if I was a bit off.
Quote from: dennisgb on December 24, 2014, 07:50:12 AM
No, doesn't make my head explode. It just means that the pilot jet is too small. If they are stock it's not a surprise. The experts recommend that you go to the next size pilot jet. You can run it like that if you want.
Damn,another mistake. I meant to say pilot jet not needle jet! No wonder i've given up working as a mechanic- too many small mistakes in a job where mistakes can be fatal
Anyways,i'll maybe leave the pilots for now.I'm considering changing the muffler soon so that would be a convenient time to rejet .And besides,i'm lazy lol
sooo to answer the OP question
buy a new set of carbs
they are about 200-300 a piece... probably want to look at the mikuni VM roundslides
then you need to have a custom throttle cable made.....
then study the jetting charts for your application.....
then buy 2-3 jet sizes couple up/down for the pilot and main
choose 2-3 needles up down....
ride the shaZam! out of it or put it on a dyno to get it as close as you can
total investment... $700-1200
or
learn to remove the carbs in 12 minutes and adjust the stock carbs to as close as you can get them.... butt dyno or dyno
once you adjust the pos... it will be about right. done... ride 20 k then buy a diff bike that is better supported by the aftermarket industry
see this is easy people......
http://www.motosport.com/au/bikemaster-extra-reach-adjustment-screwdriver
there are also bevel drive screwdrivers made for just this purpose some with degree markings
changing carbes , unless its for a peformance upgrade will be a lot of trouble
cheers Brad
Your right about that, but the reason isn't performance related. The BST is a model specific carb. Mikuni expects the motorcycle manufacturer to support them...Suzuki decided to not do a very good job of support. I've seen this over and over with carbs that were designed for the specific bikes...it's a pain, but there is info out there. VM's are open market carbs. They are used everywhere. That's why there is a ton of info.
I thought about this statement I made last night and would like to add some additional thoughts. I think the reason the Suzuki does not explain the tuning procedure or provide much information on the BST is they can't. They must meet emissions and that is why they cap the air screws. But the manufacturer's know that eventually the carbs will get dirty...but then the owner "might" tune them out of spec and they would be responsible.
yuppers
they don't want ya fiddling with them.....they are built with a couple variable adjustments and slap them on..... with little aftermarket support even from the carb MFR..... performance gains... round or flat slides... why waste time and $ on the stock stuff... they will never flow as gud as the gud stuff... so buy the gud stuff...
My guess is that the solution if you aren't handy and bring it back to the Suzuki dealer is a new carburetor.
I'm understanding why there aren't many people who understand or even want to understand how to tune their carbs.
Boss is what about a third of an inch in diameter?
Dennis i wondered why i couldnt do plug reading anymore! I know how to do the proper plug chop but still cant tell a damn what color they are.I suspected it was because modern engines run much cleaner?Now i know!
I did some minor plug reading decades ago but to be honest i usually just listened to the engine.I had nothing but two strokes back then- it's easy to hear when they are rich or lean.
Not so with these 4 strokes :-(. When i bought my GS it was running bad at full throttle under load.I did the little cheat with the choke but still couldnt tell if that made it worse or not.
All i could do was trial and error. For the record it was rich.Fixed now :-)
Skipping the intro I originally planned for this reply that has nothing to do with original post... (make a long story short)
I think the GS gets "poor" gas mileage by modern standards on purpose. It's one of the very few air cooled bikes I could even find for sale at my local dealer. I now believe the mixture is set the way it is with the factory intake and factory exhausts to run at a mixture that doesn't overheat the head.
I may be off here, but my buddy who has an airplane explained that more gas actually reduces the temperature of the exhaust manifold? If that is correct, it could explain why the GS mileage is less than stellar and the carbs can be 'tuned' for better performance so easily. I THINK they come factory running rich.
Anyone else had any observations along these lines?
The theory is correct,i richer mixture runs cooler. However i think the GS500 is usually setup a bit lean.
My theory on fuel economy is that it's not as good as it could be because its the kind of bike that encourages full throttle so often ;-)
Quote from: Zithromax on December 27, 2014, 01:32:03 AM
Skipping the intro I originally planned for this reply that has nothing to do with original post... (make a long story short)
I think the GS gets "poor" gas mileage by modern standards on purpose. It's one of the very few air cooled bikes I could even find for sale at my local dealer. I now believe the mixture is set the way it is with the factory intake and factory exhausts to run at a mixture that doesn't overheat the head.
I may be off here, but my buddy who has an airplane explained that more gas actually reduces the temperature of the exhaust manifold? If that is correct, it could explain why the GS mileage is less than stellar and the carbs can be 'tuned' for better performance so easily. I THINK they come factory running rich.
Anyone else had any observations along these lines?
Every carburated bike sold in the US market since the 70's (maybe longer) for street use have had to comply with emission standards. The GS is no exception, on an otherwise bone stock bike I went up one size on the pilot and the mains, after that the throttle response was vastly improved. To get into the states you could pretty much bet that Suzuki took an Ok running engine and then dropped the jet sizes one number to help the bike meet EPA Emission standards. Even with the plus one jetting I could get mid 60's for mileage consistently on the open road, I don't think the GS gets that bad of mileage at all.
sorry about the plug chop argument.... my last plug chop was using 120 race gas in a 2T GP bike. so not valid unless way the heck lean or rich
Thought you were going out in the canoe today instead of staying in and arguing about feckin carbs!! :D
Quote from: Suzuki Stevo on December 27, 2014, 07:18:07 AM
Every carburated bike sold in the US market since the 70's (maybe longer) for street use have had to comply with emission standards. The GS is no exception, on an otherwise bone stock bike I went up one size on the pilot and the mains, after that the throttle response was vastly improved. To get into the states you could pretty much bet that Suzuki took an Ok running engine and then dropped the jet sizes one number to help the bike meet EPA Emission standards. Even with the plus one jetting I could get mid 60's for mileage consistently on the open road, I don't think the GS gets that bad of mileage at all.
Have to agree :D
This includes pretty much anything with a carb. My ATV's all ran like crap until I put bigger jets in them.
Quote from: Ron888 on December 26, 2014, 09:35:59 PM
Dennis i wondered why i couldnt do plug reading anymore! I know how to do the proper plug chop but still cant tell a damn what color they are.I suspected it was because modern engines run much cleaner?Now i know!
You can still do a plug chop but reading it is different than the old school "tan".
It's also best to cut the plugs open so you can see the very top of the inside of the insulator. Most people don't want to waste a good set of plugs.
http://www.rays-shop.com/2010/01/how-to-read-your-spark-plugs-they-are-telling-you-whats-going-on-in-there/
Measuring with an O2 sensor and getting decent readings, then pulling the plugs and looking at them and they are essentially white, tells you that the old plug chop method may not work. I actually figured this out after working on a carb swap a few years ago and I couldn't get the right jetting and performance. That's when I bought the first O2 sensor and it helped solve the problem. Put the sensor bung right in the exhaust pipe and the gauge on the dash. Pretty cool to see the Fuel/Air mix real time and it answered the question of what was wrong.
Quote from: dennisgb on December 27, 2014, 09:57:06 AMPut the sensor bung right in the exhaust pipe and the gauge on the dash. Pretty cool to see the Fuel/Air mix real time and it answered the question of what was wrong.
If all my bikes where not EFI already...the above statement would have given me a woody so big you could hang a towel on it! :woohoo:
Quote from: Suzuki Stevo on December 27, 2014, 10:16:04 AM
Quote from: dennisgb on December 27, 2014, 09:57:06 AMPut the sensor bung right in the exhaust pipe and the gauge on the dash. Pretty cool to see the Fuel/Air mix real time and it answered the question of what was wrong.
If all my bikes where not EFI already...the above statement would have given me a woody so big you could hang a towel on it! :woohoo:
Now that was funny Stevo :D :D :D
Now to get really technical because I know you guys love that.
Stevo, your EFI bikes have a bung in the exhaust...a wideband O2 sensor is critical for the real time mapping on EFI. :D
I'm actually working on converting an old CBR engine to EFI...and the bung in the exhaust is a critical factor...and locating it correctly. I have a few holes in the pipe I had to plug. :o
It's on the bench and tied to my laptop...with the mapping software. I still don't have it right...but close. It's actually just a side project to see if I can do it.
That sounds like an awesome project. I'd like to see a pic of EFI on motorcycle. Does it have a single throttle body and intake manifold, or is it multiport? I looked into buying a kit to put EFI on my 62 VW dunebuggy (also because it's air cooled) and the picture in the kit looked really "involved" if you know what I mean.
Quote from: Zithromax on December 27, 2014, 04:04:27 PM
That sounds like an awesome project. I'd like to see a pic of EFI on motorcycle. Does it have a single throttle body and intake manifold, or is it multiport? I looked into buying a kit to put EFI on my 62 VW dunebuggy (also because it's air cooled) and the picture in the kit looked really "involved" if you know what I mean.
It's a little bit crazy if you want to know the truth...that's why it's a bench project. The engine is a 1988 CBR600. The throttle bodies are from a CBR600F4i along with some sensors and wiring. I'm using a universal fuel injection control module. There are a ton of things that had to be fabricated and sourced to get it to work. High pressure fuel pump, manifold adaptors, sensors...hall effect for ignition...the list goes on. It still doesn't run good enough to put it in a bike. It looks kind of cool tho :-)
Sledge, i went for a ww kayak run on dec 25 and a lake run on the 27th.... i can discuss technical majic at night while watching Project Binky....... droooool..... y'all brit's are friggin MAD...
Watched this last night......... http://www.bbc.co.uk/programmes/b04wwfwk (http://www.bbc.co.uk/programmes/b04wwfwk)....you need to look out for it on your side :thumb:
Was going to send out for a curry but I couldn't find the feckin menu!!!
just get a vindaloo and a warm lagar.......
So, i wound up making the screw modifications anyway. Just as a start i wanna say this:
My setup roughly: open podfilters and an takkoni slip on.
Pilot screw setup: 3 full turns out.
Against my own expectation, my first try was just 3 turns out, and it drives very nice now (better then before).
But i guess, if you want to be able to easily adjust the screws, here's what i did :)
Step 1. Obtain your pilot screws.
(http://imageshack.com/a/img540/7615/YXR1NB.jpg)
Step 2. know someone with a lathe, and you're going to drill with 4 kinds of drills
1. A centerpointer.
2. A 1.5 mm drillbit
3. A 1.98 drillbit
4. A 1.98 spacer (i guess that's the translation of it. the bit under the package on the photo under here.)
Go no further then 5mm into the screw!!
(http://imageshack.com/a/img911/8673/dpYe2f.jpg)
Here are some photos of the progress.
(http://imagizer.imageshack.us/a/img673/6020/x9y2fd.jpg)
(http://imageshack.com/a/img904/914/Ca1jlS.jpg)
5. Press a 2.0 mm steel thread trough it. i did this with the drillbit on the lathe bench. 5cm was my perfect length, it would bottom out on the drillbit, ensuring a good press.
(https://imagizer.imageshack.us/v2/1204x677q90/908/zZXc4l.jpg)
6. This is what you end up with. Simply bend the ends in a 90 degree angle.
(http://imagizer.imageshack.us/a/img537/2442/pNHunp.jpg)
7. My complete kit.
(https://imagizer.imageshack.us/v2/381x677q90/901/0nJ9by.jpg)
8. This is the final result. very handy if you feel you need to tune your screws.
(https://imagizer.imageshack.us/v2/1204x677q50/661/ndKuVj.jpg)
I wish you all a happy 2015!! :D
Too long. If you ever forget and stick you hand in that gap, you will break something.
They shouldn't be longer than the bottom of the float bowl.
Cool.
Buddha.
So, not to long if i dont forget when i put my hand in there. Thats what i was going for.