High idle on choke circuit

[Mike_H]

I have an 82 GS650GL with about 18,000 miles on it. I have just cleaned and rebuilt the carbs, (dipped, and new o-rings) and I can't seem to get it to run on choke. When I first start it up, It will fire right away, and the rpm's will climb to about 4000 and then the engine dies. This happens within a few (< 30) seconds. After that it will start with a little cranking, and try to idle at a "normal" RPM (approx 1000) but stumbles and dies (w/in 10-15 sec). After I screw around with it for a couple of minutes, it will start up off choke, and idle fine. Once it warms up the RPM will raise to about 3500 RPM, so I think I have an intake leak too...though the boots were in good shape, and I replaced the O-rings. Anyway, I'm kinda pulling my hair out on this one, so any ideas would be apprieciated. Thanks A Lot!

Mike

[edit] I did set valve clearances back to spec also.

[Mike_H]

Update: Well, I found my intake leak...one of my sync screws was not completely tight. Made a world of difference. Still idles really high on the choke though. Is it normal to do so? It kinda makes sense, cuz on choke, the engine is supposed to be getting more gas...

[tconroy]

Update: Well, I found my intake leak...one of my sync screws was not completely tight. Made a world of difference. Still idles really high on the choke though. Is it normal to do so? It kinda makes sense, cuz on choke, the engine is supposed to be getting more gas...

After it warms up check all your intake boot sync screws and all your clamps on intake and air side of carbs.Make sure your airbox is sealed good and you have a clean air filter that has been oiled.I just replaced my o-rings, intake boots and synced the carbs. The bike was running great but then started to idle up a little and my sync screw was loose also.Make sure your engine is warm when you tighten them down.The choke idle on full should be right at 4m rpm's and half should be 2thousand.Thats normal.Set your idle at 1000 to 1200 rpm's and your set!

[Mike_H]

Topic bump...

[Mike_H]

Ok, Well, just an update here. My problems only seem to get worse. I have not made any headway getting my bike running smoothly. I will give a more in depth summary of what I have done to this point. Last summer I got the bike after it had been sitting for around 8 years, in a barn. I purchased a new battery, new plugs, and and disassembled and cleaned the carbs (but no dip). I had the bike running fairly well, without a bench or vaccum sync, and just a random setting on air/fuel mixture (about 2 turns open). I could tell there were flat spots, and I know I had an intake leak, but she was ridable. A little hard to start but manageable.

This winter, I decided to fix the intake leak (new O-rings), and while I was at it I fixed the nagging things in the carbs that I had left last year (specifically, a seized/stripped idle mixture screw and a pilot jet). I also dipped everything, and replaced the O-rings with a set from Robert Barr. I tried to do a bench sync (with pins...) but I don't know if I did it right. I used four pins, and tried to get them to resist pulling out from under the butterfly valve equally. This should bring us to the point I am at now.

I still have a problem when the bike is choked (see first post in topic). I think this is due to a high idle speed setting, eliminating the actual choke circuit. Does this make sense.

I am also thinking I have a problem with my ignition system now. Cylinders 1 & 2 (from the RH side of the bike) seem to have a problem at idle. Sometimes Cyl 1 will not fire (cold header). Other times Cyl 2 will not fire (cold header). I have not seen both cylinders not fire at the same time (i.e. either one or the other, not both). I also pulled a plug on Cylinder 1 with a cold pipe, and it was jumping a spark about 0.25" to the block. When I open the throttle to about 2-3 K RPM, this problem will go away and all headers will get hot. Could this be due to carbs being VERY out of sync (i.e. one butterfly is closed, while the others are at idle position)?

I do not have the clymer manual, and have not seen anything on the ignition system in the Factory Service Manual. Can someone tell me how to check timing, and the coils out for my bike? I am at a loss here...and "gasp" contemplating actually paying someone to fix the Friggen thing. Thanks...

[tconroy]

Ok, Well, just an update here. My problems only seem to get worse. I have not made any headway getting my bike running smoothly. I will give a more in depth summary of what I have done to this point. Last summer I got the bike after it had been sitting for around 8 years, in a barn. I purchased a new battery, new plugs, and and disassembled and cleaned the carbs (but no dip). I had the bike running fairly well, without a bench or vaccum sync, and just a random setting on air/fuel mixture (about 2 turns open). I could tell there were flat spots, and I know I had an intake leak, but she was ridable. A little hard to start but manageable.

This winter, I decided to fix the intake leak (new O-rings), and while I was at it I fixed the nagging things in the carbs that I had left last year (specifically, a seized/stripped idle mixture screw and a pilot jet). I also dipped everything, and replaced the O-rings with a set from Robert Barr. I tried to do a bench sync (with pins...) but I don't know if I did it right. I used four pins, and tried to get them to resist pulling out from under the butterfly valve equally. This should bring us to the point I am at now.

I still have a problem when the bike is choked (see first post in topic). I think this is due to a high idle speed setting, eliminating the actual choke circuit. Does this make sense.

I am also thinking I have a problem with my ignition system now. Cylinders 1 & 2 (from the RH side of the bike) seem to have a problem at idle. Sometimes Cyl 1 will not fire (cold header). Other times Cyl 2 will not fire (cold header). I have not seen both cylinders not fire at the same time (i.e. either one or the other, not both). I also pulled a plug on Cylinder 1 with a cold pipe, and it was jumping a spark about 0.25" to the block. When I open the throttle to about 2-3 K RPM, this problem will go away and all headers will get hot. Could this be due to carbs being VERY out of sync (i.e. one butterfly is closed, while the others are at idle position)?

I do not have the clymer manual, and have not seen anything on the ignition system in the Factory Service Manual. Can someone tell me how to check timing, and the coils out for my bike? I am at a loss here...and "gasp" contemplating actually paying someone to fix the Friggen thing. Thanks...

you really need to order a manual. You can get one at www.themotorbookstore.com or other places.It will solve a lot of guess work then you will have a better idea of what going on when something does happen.

[Mike_H]

I do have a manual...from the factory. It is pretty worthless when it comes to dealing with carburators...BTW...I did get it running. Actually she runs pretty good now. My bench sync was out of whack enough that it was throwing me off. I had done it wrong, and finally found a post where it described the proper procedure. Thanks to all that posted....