Hi Guys,

I am still having an idle issue with my bike, it stalls while in neutral, even when warm. The spark plugs get sooty carbon on them, but i have read that may be because it's idling.. let me know if I'm wrong. I have my screws currently out at 3 rotations. Above 1/4 throttle i am fine, and the bike brings me joy.
I opened my carbs on the weekend (my first time! and I'm a girl too!   ) and found one of my floats were far from the correct height. Also one of the butterfly thingy's wasn't completely closed-  Fixed those things up. The carbs were very clean inside and the o-rings seemed alright. My Main jet is 126, my needle does not have any #4 washers on it and something really weird: the idle jet had a "30" written on it, but when measuring it with one of those diameter measurers, it seemed to be at least 40 big if not bigger. Is it common for people to drill jets to larger sizes? I bought 2 x 40 pilot jets and they "seem" to be the same size hole as the pilot jets I currently have in the bike. I don't  know whether I should try them out or return them to the store. I believe I have a stock exhaust, but i have a K&N dual pod filter which is a bugger to get onto the carb but vaseline helped.

Also, I just bought my 3rd pair of spark plugs. When spark plugs carbon foul, are they actually ruined? or can they be cleaned and re-used? My bike seems to run better with new spark plugs in it. My battery was given a "satisfactory" when it got serviced by the previous owner. Is the role of the battery just to help start the bike, or does it also have a role in the idling process? If so, this could be part of the idle problem I am having. I find if my bike is hooked up to a car it seems to idle for longer.

Please help

This forum has been a great source for information.  

Cheers, Kellie

i didnt read your post all teh way, but spark plug fouling means your running rich.;

Is your bike pre 2001 or 2001 and above.. because if its pre2001 (2000 and below) you can use srinath's carb tuning guide..

Quote from: KeLLI opened my carbs on the weekend (my first time! and I'm a girl too!   ) and found one of my floats were far from the correct height. Also one of the butterfly thingy's wasn't completely closed-  Fixed those things up.

It sounds like you had to bend one of those tiny metal tabs to reset your float height.  I'm curious whether you double-checked the float height once the carbs were back on the bike.  (If not, see my Float Height Check page for more info.)

You didn't say whether you tried to adjust the idle with the knob between the carbs...?

As far as the battery, I would guess that at idle it still supplies some of the "juice" to run the bike.  At higher RPMs the alternator should generate enough to take over completely, as well as recharge the battery.

EDIT: Links changed from sisna.com to bbburma.net

How did you close those butterflies...ther aree suposed to be slightly open and set equal to one another...
126 means its not stock jets...It must hvae had a DJ kit in it. 30 pilots drilled to 40...I have never managed to find drills that will let me drill them...
In short...not a clue but if all its doing is foul plugs I'll turn in the mix screw till it doesn't and set the floats equal and right and watch for oil useage. It could foul plugs from oil too. Mine fouls plugs at idle nd will die in a few mins of idling. But it will run just fine.
Cool.
Srinath.

Thanks for your replies guys.

My bike is 1996.
Kerry: I did not check the float height after they were adjusted, but your method of checking the float heights is very good. That's how I was originally alerted to the uneven floats. The Clymer manual says to have the float heights between 0.53 - 0.61 inches. When you have 126 main jet and 40 pilot does this still apply? I will check the heights again today.I have read in various places that the bike should idle with just changing the fuel mixture screws and the idle screw is to just make it change rpm, is this incorrect?
Srinath: I unscrewed the 2 screws on one of the butterflys and made it sit properly in the carb. I then adjusted the idle screw to have them slightly open - is this incorrect? Should I make them open using the 2 screws on the butterflys? I am suprised that you let your bike idle poorly, from reading this forum I thought you would have the finest tuned bike here!
I think one of my problems is that I am turning my mixture screws on 1/2 increments, and I think I should be going in 1/4 increments. I will try 2.75 turns, 2.5 turns, 2.25 turns and 2 turns today. I shouldn't have to go less than 2 turns right?

Another idea: If I change my pilot jet to 37.5 would that give me an improvement to my idle situation?

Does anyone have an answer to my spark plug question - can I clean them and re-use them? I'm on my 3rd set within 1 week and I don't really want to buy anymore for a while.

Thanks,

Kellie

Spark plugs can be re-used but it is not recommended. I work at an auto parts store and have tested every plug there is to buy.. My favorite by far is the splitfire plugs, they seem to make the bike run better and make it more powerful. However they are a little more expensive at 399 a piece. When you get your bike running right I would switch to those. Also if you buy them from the right store they will come with a warranty. The ones i bought from my work have a 3 year warranty.

What's the pn for the splitfire plugs?

When your bike is idling you should have no drain on your battery. It should be running off your stator (alternator). So in essence your bike should be able to idle till it runs out of gas. Batteries are only for starting, however if your stator was going out your battery would put out all the juice required to run the bike and that would equate to a dead battery...

Kellie,
You can clean your spark plugs if you want.  I have access to a glass- bead blaster and I use that to clean them out occasionally as I often run Avgas (I get it free at the airport) and that leaves lead deposits on the plug.  Just make sure you completely remove all the glass beads from the plug after you're done, with shop air.  If any glass makes it into your engine, it's going to wear some things out quickly as they are very hard.  This is a common practice used on piston powered aircraft spark plugs.  They cost anywhere from $20 to $80 a pop, so you can't just throw them away after use.  On aircraft, we bead blast the spark plugs after about every 50-100 hours of use and test them under pressure in a special testing fixture where we can see the intensity of the spark as voltage is applied to it.  Eventually of course, the center and side electrode will wear out, so there's limits to how many times you can clean and re-use them.  Once my NGK plugs' center electrode start to round their edges, I buy new ones.  As you inspect to make sure all the glass media is removed, carefully look at the insulator and make sure it's not cracked.  If it is, toss out the plug.
Of course, it might just be easier for you to buy a new $2 plug.

um...ah.... those screws on the butterflies......are lock-tited....you might want to put some more on them.....they look really neat sticking in a piston or head but you don't really want them in the engine.....when they vibrate loose

Here's the scoop of what we have found with the bike and it's idling problem - had a bike mechanic come around to check it out.

The carbs seem "okay", but the main jet is 126, pilot is 40 (?) and jet needle doesn't have any washers on it (remember the bike is running way too rich) We aren't sure if the jet needle is the right size either. I am going to find out the original specs for my 96 GS500E in regards to jets and needle tomorrow at my local suzuki dealer (in canada).

We had left the air filter off the bike accidently and noticed gas coming OUT of the back of the left carb. They checked the intake cam clearances and found the left cam to be too tight against the shim and wasn't according to specs. Also the same with the left exhaust cam. I am going to buy some thinner shims tomorrow and will let you know if this was the cause of the issue. Wish me luck and thanks for your help!

Yes left carb flooding over and valves being held open...could cause the issues most likely...Yes my bike is perfectly carbureted... but the bike has 40K miles and has not been shown any mercy so far in its life. There is enough blow by at the rings even when fully hot for the idle to completely do the hover and die routine...Its getting rebuilt sometime soon but in the mean time its getting ridden like nothing is wrong with it... I am sorta sick of riding a cruiser for the last 11 months I just jump at the possibility of riding the GS.
Cool.
Srinath.

Another update - things are looking better!

I got the right shims, and the values aren't getting stuck anymore. No fuel comes out backwards from the carbs. YAY    The timing was interesting to do, luckily all went okay. I believe I have both cylinders working now. I think all I need to do is buy some new spark plugs and I'm pretty sure it will idle well. Still unsure if it's using too much gas, we will see what color the new spark plugs will turn. If it's still using too much gas and the fuel mixture screws aren't helping, then I am going to change from the current 40 pilot, 126 main to the canadian specified 37.5 pilot and 122.5 main. Does anyone have any objections or reasons why I shouldn't?

One more thing, is there such a thing as having the wrong size Jet Needle?

Kellie

Well canadian bikes have 40 pilots...US bikes have 37.5...The 37.5's suck...
The wrong jet needle...well its possible that its an aftermarket needle...and it may not be good for it...but that is over 1/2 throttle....Idle has nothing to do with needle...You try one change at a time....and set the floats to the right level.
Cool.
Srinath.

Well with all these fixes, it is still running too rich and won't idle properly. At idle, the slides vibrate/move up and down. At idle, should these slides be moving at all? The vaccuum should be so low that it should only cause the pilot jet to suck up fuel at the front of the butterfly clip, right? I dont even have a filter on it at the moment but there is still too much fuel. I believe the slides I have on are NOT stock because there are two holes at the bottom, 1 is blocked and 1 hole is open. I am unsure if the spring is stock. The jet needle is stock, but am unsure if the needle jet is stock coz I can't seem to work out how to take it out. Anyone with any suggestions about the slides, or the too much gas problem?

The float needle cannot be replaced...cos no one makes a different one...They also close or open and have nothing to do with fuel metering. Float level does matter of course... Yours should be set to the top of the float bowl...right at the gasket level and no more, and equal on both carbs. Also what is the air screw setting...I typically set it to 3 turns out and adjust it out or in from there. If that dont work you may have to take the needles out and see if they are damaged or something or if the hole they sit in is damaged or some like that.
Cool.
Srinath.

Also one hole open and one closed in the slide is a sign it was jetted. Its common to see that ...DJ recomends it...and my home made jetting also involves that.
Cool.
Srinath.

When you say "float needle" are you referring to the "jet needle" ? and just confirming did you want me to try and set the top of my floats to gasket level? Because I did have them set to the minimum float height in clymer's manual.

Also to let you know im running with 127.5 main and 37.5 pilot right now, and it didnt fix the fuel problem. Should I continue to use these jets while troubleshooting?

Would you have any idea why my slides are vibrating up and down, would it be the float height? In regards to my air screws, do you mean the fuel screw? I have tried it from 1/2 out to 2 1/2 out.. it was rich even at 1/2 out.

Thanks Srinath for your help!

Float needle is that rubbery thing that closes the fuel flow into the float bowl. Not the jet needle.
The fuel in the floats when its on the bike should be right at the top of the bowl. Do not set the top of your floats to the gasket level. That will not let the fuel get in the bowls to where it should be.
Also put canada spec jets in it. 125/40 right?? I think so. With the U tube method test the float level and see where it is with the carbs still on the bike.
If the slides are jumping at idle your butterflies may be open too much, its un related to float level, and if at 1/2 a turn on the mix screw (yes air screw is fuel mix screw...well its the exact opposite but they do the same thing)
Also what filters and exhaust you have...may affect the jetting...but its all stock right. Make sure all the hoses are connected to the airbox and carbs.
Cool.
Srinath.

I have k&N duel pod filter and a stock exhaust.

Should I have the butterfly completely closed? because they are slightly open..the idle screw controls this right? or should I be using that other screw down near where the end of the throttle cable feeds into?

When we took the slide covers off (the big caps at the top of the carbarators) and ran the bike, it seemed to idle cleaner and faster, would this indicate anything?

Does anyone know the vaccuum specs for idle?

Thanks!

Kellie