Idle goes up when bike is warmed up

[Joel1022]

Hey gang. Got a 75 xs650. A new problem started the other day. When I started it up it kinda sputtered a little and then ran fine. Got a few miles down the road came to a stop and it was idling at about 2200rpm, never did that before. Always idled at around 1200. It's been doing it ever since. I've been doing a lot of research and have checked and adjusted everything I know to do (timing chain, valves, idle screw, air leaks, hung up throttle cables... etc.) I'm stumped. The carbs were rebuilt. New jets,ultrasonic cleaned. It was running great.

 

[5twins]

Have you serviced the advance rod? It needs to be greased or it can start sticking once it dries out. That makes the timing stick at full advance and that causes a high or hanging idle.

 

[Joel1022]

Have you serviced the advance rod? It needs to be greased or it can start sticking once it dries out. That makes the timing stick at full advance and that causes a high or hanging idle.

No. Can't believe I forgot to check that. Lol. Thanks.

 

[peanut]

have you checked that both your Choke valves are returning fully and sealing completely after using the choke.? also none of the various plugs and vacuum take off screws have loosened or been lost
Hanging idle usually means an air leak or lean pilot circuit if the carbs are at fault but its worth checking everything including any adjustment screws that may have worked loose due to vibration.

 

[Joel1022]

have you checked that both your Choke valves are returning fully and sealing completely after using the choke.? also none of the various plugs and vacuum take off screws have loosened or been lost
Hanging idle usually means an air leak or lean pilot circuit if the carbs are at fault but its worth checking everything including any adjustment screws that may have worked loose due to vibration.

Thanks. I'll double check that.