Can start it when engine is cold, but when its warm and i stop the bike, the motor stops working

[Tomas38]

Hi all,
yesterday i tried to ride my "new bike" (i bought it this year) YAMAHA XS 400 SE 1982, when the engine was cold there was no problem to start the motorbike and ride on it, but when i stopped at the lights the engine stopped working and it was not possible to start the motorbike again, i had to wait half and hour then was the engine again cold and when it was cold i had no problem to start it again and ride on it, but when i stopped it it happened again the engine stopped working and it wasnt possible to start the motorbike .

Do you have some experience with this problem? Thank you for your answer!!!

 

[NewHavenMike]

Why dig up a thread from the grave only to start your own thread?

I cant really go in too deep here right now but, you should be making your adjustments and tuning the bike when its FULLY warmed up. That doesn't mean leave it running for 5 minutes and youre good either. You need to ride the bike for a good 30 minutes. Then you can tinker with settings. Did you replace the needle and seats in both carbs? Also, remove the fuel line from the carb and see if fuel flows freely.

Youre probably too rich, which could explain it running cold and then not running when its warmed up. Stick to stock jetting and get a plug chop before you automatically get bigger jets. I have an aftermarket exhaust and aftermarket filters and I still had to go down in jet sizes...

Check battery voltage, could be a bad battery too. This situation happened to me and it was a dead battery. Id have to wait for the battery recover a little and then Id get about 30 seconds of run time before it died again.

 

[Tomas38]

Hi, thank you for your response, will try your recommendation, i appreciate every advice because im really beginner its my first motorbike