When messing with my carbs today I decided to start the bike without the air box on, just to make sure slides weren't sticking. When I did this I noticed that air and gas were coming OUT of the left carb.
I'm guessing the only way this could happen is if the intake valve is not seating properly.
Is this a symptom of simply neededing to check and shim the valves or could this be something much more serious (valve seal, etc)?
if it was a vapor thats normal (single carb) but sounds like they need to be balanced.
check the valve clearance but i think you will find it is fine.
check the vac tubes to the carb to be sure there pluged in right
vac tubes are fine and I've done the WD40 check for vac leaks
I figured it it was actually blowing out somewhat forcefully like it was it would have to be a leaky intank valve
Tis caused by a lean running condition. Or so I think.
So is that the answer then - just more carb tweaking? You guys don't seem too sure.
I agree with rangerbrown. A little bit of fuel/air mist coming out of the carb at idle isn't too unusual (although I haven't seen it on my GS), but the fact that it's only coming out of one carb indicates that the carbs are out of ballance or your intake valve has to little (or no) clearance from the cam.
First try ballancing the carbs, if that dosen't help or you are unable to get them to ballance, check your valve clearances. You may have a tight intake valve. It's easy to check your valves, all you need is a feeler gauge, but if you need to adjust it, you need to buy a $20 special tool. If the valves are tight, you can remove the shim and sand it down till the clearane is within spec instead of getting a new one.
It's not a valve thing, if there was no clearance at the gap it wouldnt run at all, or it would run but like complete ass. I'm going to say your a bit to lean on the bottom end. Carbs can be a little tricky to tune with no airbox.. try turning the mixture screw out a little bit, and sync'ing the carbs never hurts.
Do you normallt run the bike with an airbox on? When you say gas is coming out, is it pouring out? or does it come out like a puff of mist? and you can hear it pop?
If you normally run the bike with an airbox I wouldnt worry about it.
That is what happens if you have a turbocharger and very aggressive cams with lots of overlap... but I'd guess you have neither...
+1 on if it runs fine normally, not to worry about it
Haha - no turbo or agressive cams Lima.
I normally run with the air box. I've just had a lot of problems with the hanginging idle which it turns out was a result of the PO never replacing the covers on any of the vacuum inlets. Carbs were still out of wack after i cleaned them so I've been adjusting float level and air screws trying to get them right. I was only running with it off to check slides.
Vapor was coming out, Gas was not pouring out - that float is leaking a little but it was very slight as in a few drops a minute, Gas was coming out of one of the little holes on the airbox side of the venturi I dind't notice it till I pulled the airbox off and will attempt to adjust it tonight.
Bike runs great on the high end - idle is just junk still. I've fixed the hanging idle but now if I blip the throttle while idling the RPMs stumble and drop and sometimes the engine dies. If i get the RPMS over about 4k before dropping the throttle its great and settles back fine. I'll try adjusting or replacing the one float valve then playing with the mixutre screws to it running right under 4k RPMs
Guess I'll buy the stuff to make the $5 balancer and balance them while I'm at it. I sure hope she runs sweet after all the time I've been putting into this. Oh well, I'm a noob so I guess this is sorta my initiation.
The carb balancer won't do you a bit of good if the valves are out of spec. Make sure that everything else is right (valves, float height, new o-rings, clean jets, etc.) before you try balancing the carbs or you'll just end up frustrated and the bike still won't run right.
Hanging RPM's when you let off the throttle are also a symptom of lean air/fuel mixture. If I was a betting man I'd say thats your problem. Adjust the mixture screws out a bit, and see what happens.
I was hoping I could avoid having to tear into the valves until this winter when I'm back home and I can use my uncles giant, heated and fully stocked garage. I'm working in an apartment parking lot right now.
I was going to get the float issue sorted out and pull out the idle jets to clean them and then once the stubling revs at idle are taken care (hopefully just tweaking mix screws) of I'd try balancing the carbs.
I rebuilt my carbs, adjusted my valves and changed my chain and sprockets in my apartment parking lot.
Seriously though, you can't balance the carburetors if everything else isn't right. It's not that it's a bad idea. It can't be done. If the cylinders aren't running the same (at equivalent throttle), then the carbs won't balance. You'll just throw it out of whack.
The best that you can hope for is to get them running evenly. What I did was to take a spark tester and ground out one cylinder to a cooling fin while letting the other cylinder run the engine. I switched cylinders, adjusting the balance screw until they were running at the same speed. This worked best for me until I got my valves adjusted.
Would just pulling the cable off one of the plugs have the same effect?
I had a Ninja 250 that did the same thing, valves were all very tight. The bike would rock with some of the backfires through the carb, not the safest feeling when you think about the airbox location.
Quote from: mjn12 on September 13, 2006, 01:11:29 PM
Would just pulling the cable off one of the plugs have the same effect?
It will, but it can cause....undesirable electrical failures. As cheap as a spark tester is, and as costly as a coil is, and as much as you'll probably be running without the boot on the plug, go buy the $8 spark tester.
So I've had the carbs back on all weekend. I've been riding but the problems not gone. The idle still climbs and once I go to get moving its a little unresponsive. I basically have to get the revs high, then let the throttle out to keep it from bogging down. I did notice that the O ring on the little plastic 'L' shaped tube that is part of the float assembly was a little loose (it rotated freely). Can anyone clue me in on whta the purpose of that is?
Can I get ahold of a rebuild kit for the '00 carbs? Will the rebuild kit that is marked for the 93's work for me?
I'll be checking the valve clearances this weekend once I get ahold of a feeler gauge so hopefully I can eliminate that as part of the problem.
Its not stopping me from riding but it makes me not trust the bike when I want to start moving and thats pretty scary wen I'm riding in heavy traffic.
Quote from: mjn12 on September 17, 2006, 04:45:02 PM
So I've had the carbs back on all weekend. I've been riding but the problems not gone. The idle still climbs and once I go to get moving its a little unresponsive. I basically have to get the revs high, then let the throttle out to keep it from bogging down. I did notice that the O ring on the little plastic 'L' shaped tube that is part of the float assembly was a little loose (it rotated freely). Can anyone clue me in on whta the purpose of that is?
Can I get ahold of a rebuild kit for the '00 carbs? Will the rebuild kit that is marked for the 93's work for me?
I'll be checking the valve clearances this weekend once I get ahold of a feeler gauge so hopefully I can eliminate that as part of the problem.
Its not stopping me from riding but it makes me not trust the bike when I want to start moving and thats pretty scary wen I'm riding in heavy traffic.
How were the valve clearances?
The rebuild kit will work. See this post (http://gstwins.com/gsboard/index.php?topic=26738.msg281179#msg281179) for details on it. You need to replace all of the o-rings. The ones on my 99 were completely broken down. I doubt yours are any better.
I forget the purpose of that o-ring and the part it goes over.
I'll be checking the valve clearances this week as soon as I get a chance. Since the bikes rideable its hard to tear it down with the great weather we're having this week.
Seems as though partsnmore is out of stock on the rebuild kits - any other good place to get them?
EDIT: Jets are on their way from the dealer, I had to buy in sets of four but the prices were almost as good as buying two seperately from sudco. If anyone wants a set of #40 pilots or #125 mains let me know. I'll sell for cost plus your desired shipping and any transaction charges (ie. paypal charge) If memory serves me right it was 10.xx for the 4 pilots and 15.xx for the mains (for the sets).
I'd like the pilot jets, I've been meaning to get them for a while now, but I'm lazy so I haven't. I'll send you a personal message with some details.
On a side note, the jets shouldn't have anything to do with your problem, but rebuilding and or cleaning the carbs isn't a bad idea, and I guess while you're in there you may as well do the jets, anyways good luck and talk to you soon.
Good luck :cheers:
So what size jets did you order?
mjn12, I just sent you an e-mail with my info :)
Chris_B, READ HIS LAST POST :flipoff:
Ducati - you got the pilots when they come. I replied to your email as well.
I was told by multiple people that it was possibly a result of running lean, However, it doesn't seem I can make it run rich. I figured a rejet couldn't hurt.
So far I have:
Cleaned carbs
Adjusted Float levels
Adjusted mixture screw
adjusted idle
confirmed choke is not sticking
Checked for vacuum leaks at carb boots
Checked for vacuum leaks at inlets
I have yet to check valve clearances but I'll probably do that when I go home or maybe this weekend (its nice out, I really want to ride).
I'm also gonna order a new o-ring or two from bike banit since partsnmore is out of rebuild kits and replace anythign in there I considered iffy.
Once i know valves are in spec all I can do is balance and hope somewhere along the way my problems are solved. Otherwise I'll have to throw in the towel and get
either a dealer or my much more knowledgeable uncle to help me when I move back to ohio in december.
Cool, I'll finally take care of the bogging in the midrange with those jets, thanks :thumb:
As for your problem, it sounds like you've checked everything but the valves, which I've thought was the most likely culprit from the begining. Pay special attention to the intake valves, and even if they are within spec (doubtfull) but at the minimum clearance, try opening them up to middle or upper end of the clearance range to ensure that the valves are fully closing.
Some may disagree with me but you can remove the shims and sand them down. Just get some 600 grit wet sandpaper, and wetsand the bottom of the shim. Place the sandpaper on a piece of glass to make sure that it stays flat and you should be fine.
Also, you only need feeler gauges to check the clearances but you need a special tool to remove the shims. I've found an inexpensive place to order them here
http://www.pitposse.com/vaadto.html it's the $18.90 one.
Have you checked your compression yet?
Hope this helps
good luck :cheers:
I have not checked compression yet. That was going to be my next step after the valve clearances.
Compression testers I've seen online seem to be running upwards of $100 in cost, definately not in my range. I have to get the bike inspected for registration within the next 10 days so maybe when the shop is inspecting I can have them check that real quick for me.
rent it form advance or auto zone
I was going to recomend doing the compression test to tell you if the valve is leaking or not. If you can't get your hands on one easily and cheaply don't worry about it, just check the valve clearances. If the clearances are off then you know you had low compression. If you adjust the valve clearances and it solves your problem, your compression is probally just fine.
Have you checked those valves yet? If you have the feeler gauges, it only takes about two hours if it's your first time. No biggie.
Good luck :cheers:
I've got the feeler gauges and the telescoping magnetic picker-upper dealy (is there a more technical name :dunno_white: ). As soon as the tool for depressing the buckets shows up from pit posse I'll check those clearances. I'm betting theyll be off and I don't feel like tearing into it once to find that out and again in 5 days when the tool shows up so I can pull them out and order some new ones. The dealer where I'm getting the jets stocks most sizes of shims so when the jets show up I can probably just get everything at once. The dealer is half an hour drive from me and I want to fight my way back home through D.C. rush hour traffic as few times as possible.
Cool :cheers:
you can get a compression tester for ~$20 from walmart or ~$30 from Sears. Or, as rangerbrown suggested, you can rent one from a major autopart store.
Checking the compression is something you'd do before checking the valves. If the valves are tight, then you'll have low compression, and checking compression is A LOT easier than checking the valves. If compression is with in spec, then it's not your valves or head gasket or rings or anything like that. But if you're checking your valves anyway, I guess it doesn't really matter.
$20 at walmart sounds good,
Will i need to find one to fit the spark plug holes on the GS? If so what size?
Edit: Nevermind, spoke before I searched. Its 12mm. I got roped into playing tennis tonight so no time for the GS. Thursday I'm supposed to be at the gym... maybe I'll just have to skip that.
I checked my cleanances, the intakes were off by as much as .1mm (I went from 2.65 to a 2.55), one of the exhausts was ok and the other was only .5 off. However, I have to make the 40 minute trek to the dealer to pick up another shim. The guy there first told me the shims were a buck a piece, so I was gonna pick up about 10 of em in some various sizes since I didn't want to have to make that trek again and I had zero clearance on all the valves that were off so I couldn't figure out what size I needed. When he rang them up he tells me "shaZam! duuude, those are $9 a piece, sorry about that. I left with three and it turns out I needed 2 of the 2.55's so I get to go back tomorrow and make the exchange, and maybe even trade in my old ones for half off the cost of the ones I bought. If they don't take them I'll ship em to whoever needs them.
I've got my new main jets but still waiting for the pilots :cry:
well, theres your problem :o zeron clreance
Update: New pilots showed up at the dealer the day after I picked up the mains I ordered. I've got them in my carbs now so now I'm at
125 Main
40 Pilot
Needles with a single #4 washer in addition to stock spacers
Still waiting on part number 17 from the carb fiche on bikebandit. Its that little o-ring that goes on the float assembly. I dont KNOW that anything is wrong, but I trust em and I'd feel better if I replced them when I had the chance. I think I'm gonna put the bike back together and see how it runs with the old o-rings. If its running alright then I'll put those on some other time.
My $2.99 carb balancer is made and the fancy $20 walmart compression tester is standing by. I figure I'll balance the carbs and see what happens. If the carbs balance and my problem is solved I'll return the compression tester to save the cash and just ride until it gets too cold out.
Still need to figure out where I'm gonna mount the fuel filter. Its one of those little glass and metal ones. I don't have a frame petcock (putting one on this winter), the lines just drop from the tank straight to my carbs so any suggestions as to how/where to mount this thing would be appreciated. Would letting it rest against the crankcase be too much heat? Should I plug it in closer to the tank?
Did you get your valves all sorted out? If so, I bet once you get your carbs back together and ballanced, it should work just fine. :thumb:
You can put your filter anywhere between your carb and the tank. Being glass and metal, I don't think you need to wory about heat :cookoo: the rubber fuel lines would melt and the gas burst to flames long before the glass and metal would melt. You only need to wory about something hitting it and breaking it. Just stick it in the line and make sure nothing will hit it, or tie it off to something to protect it.
For $20 the compression tester would be nice to keep. Whenever you clean your plugs, you can check the compression, that way you can see if your rings or valves are starting to go. You get a warning when you need to do a rebuild long before your bike dies, so you don't get stranded.
You should figure out how much those jets will be to send them my way. I'd like to get that last little bit of my carbs sorted out too :thumb:
Thanks and good luck :cheers:
Check your email regarding the jets. I'll send them via usps priority or something, you should have them next week
Cool :thumb:
I have a plastic fuel filter sitting on my engine case with no problems.
Alright, with the new jets, clean, happy carbs, and dialed in valve clearances the bike seems to run much better. Its not all together yet - still working out the gas tank issue (my other recent post).
The carb balance worked great, best $2 I ever spent.
Once I get the tank cleaned I'll be able to ride and see if all this was really worth it.
You'll have the thing running great just in time for the snow :laugh: oh well. At least it'll be running. Did you check your compression or are you still planning on taking it back? It should run just fine either way.
good luck :cheers:
Nah, haven't messed with that yet. Maybe if I'm bored this weekend.
So I checked compression - the gauge reads 110 on both cylinders (this is lower then spec but I don't think the 20 dollar gauge is accurate). Pressure holds until I hit the bleeder on the gauge so I don't think I"m leaking anywhere
Idleis still HORRIBLE. Bike roars once its up past 5k but I can't get it to run consistently below that.
With the #4 washers on the needle the bike seemed way to rich. I could smell the gas in the exhaust, mix screws weren't helping.
I pulled the washers out, this helped a little, I'm letting the engine cool a little, then maybe try playing with the mix screws a little more, maybe I'll have to take them out past 3 turns since I don't have the washers on. Grrrr.
I'm guessing that its that o-ring that I was questioning that is giving me the problems. I'm ordering rebuild kits tonight. After those are actually rebuilt I'll know its just tuning.
Any carb experts in the MD area? I'll buy you beer, food, hookers, whatever if you can come here and fix this.
First off, many thanks to wrecentwryder for hooking me up with some correctly sized washers.
I went to see if they would fix my problem yesterday and before dropping the washes in I tried to start the bike one more time to make sure I didn't just need to fiddle with the screws a little. However, instead of starting the bike just cranked a few times an eventualyl backfired. I tightened the fuel scews to 2 turns and it ran for a little while.
After "balancing" the carbs I found out that my "balancer" had a bunch of water pockets in one of the tubes, close to where it plugs into the carbs. This was before I rebuilt it so that it would not suck water into the carbs. This water in the wrong place would make it extremely innacurate and make me send my carbs way off balance. If I remember right i had to turn the screw 2-4 turns (can't remember exactly now) to get the old balancer to show them as balanced.
Now I checked spark when i was testing compression, and compression was ok and i saw nice blue sparks on the plugs so I'm assuming electrical is ok. I knwo the valve clearanecs are good since I just did those, The carbs were just cleaned and the gas that comes out of the bowls is nice and clear (even though my fuel filter is just starting to look a little ugly).
I can't imagine my problem could be anything but carbs. Since the jets are new and clean, needles are shimmed 1mm with #3 washers Fuel flow is good and float levels look right. Could it be possible that the carbs are so far off balance one is running crazy lean and one is running crazy rich enough that neither will start and all I get is a build of gas from the rich one and an eventual backfire? (Man its loud too. My ear must have been ringing for 3 hours when i was kneeling close the the exhaust and trying to start and it did it).
Btw, thank you all for bearing with me. If you are getting tired of hearing about this imagine how I feel. I'm pretty sure hair is falling out of my head because of this. I'm only 20 so thats not good.