Starts fine, runs fine... then stalls!!!

[iDodgimus]

I've had this happen to me twice now. My 81 GS650E starts fine (a little smokey in the morning, but i hear thats a common minor oil leakage) and runs great but twice now after riding for an hour or so it'll stall when I'm stopped at a light. It's a pain to get started again, and tonite I my mate had to push me to bump start it...

It happened once on Monday (my first day of with the the bike) and it's been fine all week until tonite!!!

If my description's not too vague, can anyone suggest what it might be?
I'm only a month into my biking career so I'm pretty clueless (for now)... I'm just hoping for some ideas so I can talk to the mechanic if I take it into the shop tomorrow.

I live in Vancouver, BC so if there's anyone local that could take a look at it I'd prefer to work with you than take it to the shop... there's beer or cash in it for ya

[iDodgimus]

after reading the 'how to get lots of answers' thread...

1981 GS650E
32xxx kms on the engine.
just bought it, but apparently been running all along.

other symptoms include:
smoking on cold startup.
slight oil leak coming from around the 2nd carb in from the left (from it, or above it)
occasionally theres a bitter, chemical type smell. not gas, could be the smoke?

[Nessism]

The petcock connects to the 2nd carb via a vacuum line. Maybe that leakage you have noted is gas; failing petcocks often send gas back down the vacuum line and into the engine.

Another thing to do is a compression check. Your engine is burning oil so a quick check is in order to see how the mechanicals are. If you have not checked the valves, now is a good time as well. Low compression could very well cause the symptoms you describe.

Good luck.

[Greg O.]

Take a look at the spark plugs to see if they are clean, or do they have a lot of oil build up on them. If they are black, that would indicate a rich mixture. If #2 plug is black this may indicate that you are getting gas from the vacuum line going to the petcock as Nessism suggested. While you have the spark plugs out do a compression check. This should be done with the engine warm, and the throttle wide open.

Greg O

[chef1366]

Is the starter turning after you stall to warrant a push start?

[bradleymaynar]

I'd think the stalling could be a battery issue. Especially since you say it's nearly impossible to restart.

Brad bt

[iDodgimus]

thanks folks

The starter turns but never actually caught last nite. It started ok this morning.

I did notice today that gas is leaking from what appears to be the seal/gasket at the back of the 2nd carb - it was clean, whereas the other leaking was more yellow... could it be the same?

Really appreciate the help on this, keep it coming...

[donasmello]

I would say it might be a bad petcock and bad spark plugs. I couldn't start mine for like 2 weeks and I finally looked at plugs and they were all black (PO said they were brand new). Replaced them and started right up. Now I'm leaking gas profusely when I come to a stop which I'm pretty sure is a bad petcock because when I had the gas tank off the gas would run out in all 3 positions on petcock.

[pntrdave]

This may sound simplistic but.... My bike starts and runs fine with a little choke first thing, but if the choke is left up even a little bit it will die at the first stop and will not restart until I make sure the choke lever is all the way down. It will crank and crank but just won't start.

[iDodgimus]

thanks ptrdave but i'm pretty sure that the choke's ok - the cable's actually not connected, so i usually pull the choke manually if i have to, and that way it's never left open... interestingly tho, if i pull the choke all the way out it dies right away.

[iDodgimus]

what a lovely fella

my bike started fine today and refused to start once i filled up at a gas station... luckily there was a nice dude named Frank who spent some time with me and tried to diagnose the issue - here's what was found:

engine was flooded, and plugs werent sparking - Frank suggested that if the plugs werent firing correctly this would flood the engine with unburned fuel.

we poked around a bit more and and found that the fuses were old and falling apart, replaced with new 10amps - all of them, then i later found that the main should be 15amps - will this cause a problem?

after replacing them we found that it didnt make a difference and the charge being sent to spark plugs is low, very low!!!

Frank said that it could be a coil issue or a points issue as the starter switch turns over but doesnt catch - any second opinions?

thanks Frank, hope you got home safe :-D

[chef1366]

Clean all the connectons for the ignition. (Coils, igniter and crank trigger) Get the battery checked. Also clean the fuse block.