82 gs650 stalls when throttled

[Anonymous]

I am a new owner of an 82 gs650 that sat for about 15 years. It only as 29000 km and is in grea shape. I have recently begun working on it. At first it wouldn't start at all. I rebuilt the carbs and now it starts great, but only with the choke full open. when I slide the choke lever to the right (open/closed? i really don't know) it stalls. Also, when I try to rv it, it stalls. Can't wait to get it on the road. Please someone help the newbie!

[Anonymous]

GS's are very cold blooded. They have to be really warm to run properly without the choke.
Do you still have the stock airbox and filter installed? A GS does not run well without an air filter.

[Anonymous]

Everything on this bike is original down to the air in the tires. The air filter is clean and I let it idle for about 10 minutes.

[Anonymous]

hey fifer

now ya mention you're a newbie ... but that you've rebuilt the carbs ... what all did this entail... a Carb rebuild often takes hours even at a shop ... so as a newbie, I would expect this to have taken a fair amount of time ... and also, as a newbie could see reassembling the carbs incorrectly to perhaps be the cause of such a problem...

now, being a newbie to the tech side (and pretty much the riding side too, with 2 summers just about under my belt) I might hazard a guess that you are not getting enough vacuum when the throttle is cranked ... such that the idle air/fuel mixture is adequate to keep it running, but when cranked there is not enough pressure to suck the right amount of mixture through ...

don't go by that though, as it's probly just me pipe-dreaming hehe..

[Anonymous]

The rebuild took me about 5-6 hours by the time everything was cleaned and put back together. I have much experience as a backyard mechanic in cars and trucks, but this is my first attempt at bikes. Would the float levels play a role in this problem, as i didn't reset or adjust them. If not, can I find out more about the vacuum and how to adjust that? I also hear a hissing sound coming from the area of the gas cap once the bike has cut itself out.

[Anonymous]

First, choke lever to the right should be "off". Work the lever and look under the left side of the tank to see the bar that operates the choke on each carb moving. It'll move towards you for "on" and back in is "off".

Your problem sounds like blocked pilot jets in the carbs. I know you cleaned 'em up but it can be a hell of a job getting ancient petrol out of every little jet opening (it turns to a horrible varnish with age) and powdery rust from the tank can get in there too sometimes. My record is three strip downs before I finally cleared all the gunk out.

Before you take the carbs off again though, check fuel and vacuum lines are all okay and make sure the tiny air vent in the tank cap is clean. That hissing sound may mean its partly blocked. You could check that by seeing if the bike runs better with the tank cap off.

[Anonymous]

CONGRATS!!!
I too am a proud newbie owner of an 82 GS650G. and have stumbled upon a new-found love. She is in Cherry condition, 18,000 miles, 1-owner (besides me), never been laid over, garage kept, not a bit of rust, not a scratch in the paint.. and best of all! She was FREE!.. I too had a lot of problems with my carbs, turned out the carb to intake boots were leaking air badly, the rubber was in good shape, but the air was coming in where the rubber attaches to the metal flange that bolts onto the manifold. Also, Air filter condition is critical!, I tried putting in a different air filter, and different types of foam and that bike ran in 100 different crappy ways. get an original NEW air filter. and ensure that your airbox is sealed correctly ar each opening. the hose clamp. It could be that the reason it runs good with the choke on is because it is evening out the gas/air mix to a point where it will work. Applying the throttle allows more air passage in, and when there is too much air available it
will stall. check your plugs, They are probably light gray or white. Lean condition.
Also, you mentioned that you cleaned the air filter, did dampen it with oil before re-installing it? The oil added to the air filter also adds a restriction to the amount of air allowed into the carbs. What I did was stuff a t-shirt into the air-box and completely shut off the air flow. I tried starting it and slowly pulled out the t-shirt bit by bit until I hit the sweet spot where the air to fuel mix was perfect and the bike would run fine. You might give that a shot. Like I said before, Im a newbie too, but Im learning and loving every second of it. Good luck
Tom

[Anonymous]

I was and am having a carb problem so I asked about it and Keith mentioned the air leak problem. I checked the airbox as he suggested, sealed the filter/carb boots, and checked the filter. It was a new filter but it just flopped around in the airbox because a foam or rubber gasket was missing and allowed a 1/4 inch space between the filter and the airbox itself. I put in some adhesive-backed foam insulation and when I get the carbs back on I'll know that the air filter to carb passage is OK.

Harrison

[nabrams]

I just wanted to add that air leaks at the boots that attach to the airbox (containing air filter) can be just as bad as air leaks at the boots that attach to the engine. I know this because I had the same problem. My bike had been sitting. It would run at idle and stall when giving gas - just like yours. I cleaned the carbs several times. After sealing the leaks (with silicone), the bike ran smooth as silk. That airbox and air filter were designed for a very precise air flow rate suitable to your bike. Any air leak will throw the whole thing out-of-whack. The air filter element is critical as well. If it's rotted, you can bet you're bike won't run right.

[Anonymous]

Thanks for all the info, I will try sealing the boots. I also noticed a "crackle" sound occasionally from the exhaust. I also noticed while on the centerstand that the oil light would periodically come on. I forgot to change the oil, which I have now done. Any thoughts

[AOD]

GS's are very cold blooded. They have to be really warm to run properly without the choke.

20+ year old coils and wires, and dirty carbs are the reason for that. my GS with cleaned carbs is ready to ride in about 2 minutes if i want.

~Adam

[earlfor]

Gotta agree with that one, My 79 750 if left sitting for a week, starts instantly on choke and in less than a minute, I can push the choke to off and ride away.

Earl

20+ year old coils and wires, and dirty carbs are the reason for that. my GS with cleaned carbs is ready to ride in about 2 minutes if i want.

~Adam

[Anonymous]

:roll: Thanks for all the tips. I have just put the carbs back together AGAIN after adjusting the floats to 22.5 mm. I also sealed the boots with silicone and of course I had ahrd starting problems. I have to have the throttle almost full to get it to fire without stalling. Besides that I now have an oil leak from the filter cover. Can I use a gasket type sealer around this area being careful not to get any overflow into the oil itself. The good news is that she will rev now with the air leaks sealed, bad news is I still can't ride her. I can get a ride with a little help from my friends! Thank you for all your posts!

[Anonymous]

Also forgot to let you know that I replaced the gasket in the filter cover and torqued bolts to specs. Oil leaks faster when the bike is shut off.

[Anonymous]

Hey guys,
I am also a newbie to bikes. My friend gave me an '81 GS550L, with everything rusted solid on it. So far, the brakes are free are working, the shifter is working, clutch works, got new tires, and have my carbs soaking at the moment. The pilot jets were solid with residue at the bottom side and took quite a bit of work to clear the hole. I could start the bike when I got it, but if I so much as looked at the throttle it would kill. I also have 2 cracked float posts. Time to get some JB weld. Oh, Impact screwdrivers are my latest favorite invention.