Bike will start, but then will stall, and not start again!!

[DNSLOAN]

I just bought a 1981 GS650. The guy drove it to my house, and I rode it around for about 10 minutes. It rode fine. The next day, I tried to start it, and it would start first time, but after a few seconds it would die. This pattern happens everytime.

I've taken the fuel line off the tank, and the gas comes out of the tank just fine. I checked the vacuum line, and it sucks. The other end of the fuel line goes to the carbs, and I couldn't access that end to see if it was blocked.

Are my carbs gummed up, or is it some other problem?

[GQROD]

I just bought a 1981 GS650. The guy drove it to my house, and I rode it around for about 10 minutes. It rode fine. The next day, I tried to start it, and it would start first time, but after a few seconds it would die. This pattern happens everytime.

I've taken the fuel line off the tank, and the gas comes out of the tank just fine. I checked the vacuum line, and it sucks. The other end of the fuel line goes to the carbs, and I couldn't access that end to see if it was blocked.

Are my carbs gummed up, or is it some other problem?

Check your plugs to see if they are fouling out or lean.

It may be running out of fuel or getting too much fuel.

Start with the plugs and go from there.

[Geoff4130]

Mine would do this. One day it took 20 minutes - no kidding - to get it started. Other times it would start then die then not want to start. I replaced the plugs and it's 90% all better. Still from time to time it runs a bit then dies right away. In that case I hit the kill switch then turn it back on then it starts right up. The plugs are supposed to be gapped at .024-.028 and the ones in it were at about .040, it was bad. My mpg went up a ton too.

[hikermikem]

I just bought a 1981 GS650. The guy drove it to my house, and I rode it around for about 10 minutes. It rode fine. The next day, I tried to start it, and it would start first time, but after a few seconds it would die. This pattern happens everytime.

Tell us some more about the bike - any mods, recent maintenance, replaced parts, known issues (besides the one you've posted)?

[chef1366]

Clean the carbs and check the vent lines off the carbs and the vent on the fuel cap.