Fast idle then shuts off. Help!

[guitarmaker]

Hi folks, I just bought my first XS650. It seems to be a well taken care of 1977. The previous owner claims he rode it regularly until about 8 months ago. But, I've been having some trouble starting it keeping it running. I took the carbs apart and cleaned them and then it started right up, however when I give it some throttle and then roll off the RPMs stay up. The cable is not sticking and if I adjust the idle speed screw it slows down but I have to put it right back into position or it will shut off. Also, if I leave it idle without giving it any throttle, it will shut off after a few minutes. After a few restarts, it became harder to get started again. Is it possible that something is sticking internally? It seems to me that it is a gas flow or regulation issue. Did miss something while cleaning the carbs? Any help would be appreciated. Thanks in advance.

 

[xjwmx]

The getting harder to start might be the battery getting weaker. Did you adjust your cam chain and your valves? You need to do that before any carb work. Otherwise you ca have a "Carb problem" that no amount of carb work can fix Then if no joy, check for big leaks in the intake side of the carb, like a vacuum take off without a hose or cap on it, or a very loose clamp. If still no joy look for mechanical badness, like maybe the butterfly hanging up or the throttle cable hanging up. Also if the choke was somehow stuck on it might cause something like that.

 

[jd750ace]

Sounds to me like a classic lean condition. Gets worse as the engine gets hotter. The pilot jet's emulsion tube holes are probably plugged up, so it's running off the mixture screw fuel alone. Did you pull all the brass bits out and clear all the passages? Did you flush passages with carb cleaner, and blow them out with compressed air? Did ya get the pain in the butt boots between the airbox and carbs back on good?

Re-check your work. If it did not run before you started, it is better, just not right yet!