Carb won't close all the way

[jmerlino]

My right side carb sometimes doesn't close all the way. I've ascertained that there's slack in the cable, and I can get it to close all the way if i push on the lever with a screwdriver, but just releasing the throttle doesn't always seem to do it. I'm tempted to try to find a stronger spring to put in there, but if there's another problem, I'd rather address it that way. (Note: I just rebuilt the carbs, but this problem was there before that, and it's still there now.)

Any ideas?

[rrg2]

The first thing I would check is the junction box under tank. If I remember correctly this happened on '82R100-RS I had. Also if cable is to loose it will hang up at ferrel. Good Luck.

[GlobalRider]

I'm tempted to try to find a stronger spring to put in there, but if there's another problem, I'd rather address it that way. (Note: I just rebuilt the carbs, but this problem was there before that, and it's still there now.)

Any ideas?

Disconnect the cables...does the carb still stick open? If yes, then it has nothing to do with cables.

Did you do a complete rebuild where you put new O-rings on the throttle shaft? If so, did you tighten the throttle plate screws with the plate completely closed so that the plate was centered while doing so? That means backing off the idle adjust screw so that you can fully close the throttle plate. I hope you didn't forget to peen the screws if you did replace them.

I also applied Dow Corning High Vacuum Grease (made for rubber applications) to my O-rings for long term, high temerature lubrication.

[jmerlino]

Did you do a complete rebuild where you put new O-rings on the throttle shaft? If so, did you tighten the throttle plate screws with the plate completely closed so that the plate was centered while doing so? That means backing off the idle adjust screw so that you can fully close the throttle plate. I hope you didn't forget to peen the screws if you did replace them..
I did not remove the butterfly. I'll check it without the cable on it.

[88bmwJeff]

My guess is that the O ring on the throttle shaft has deteriorated. I would replace the O rings and lube/grease accordingly.

It has been suggested to me to use blue Locktite instead of peening the screws. It makes removal easier in the future. Be sure to grind or file the screws holding the butterfly in place on the throttle shaft before removing the screws or you'll strip the threads. Make note at the position and orientation of the butterfly when removing. It needs to go back in the same position. There is a mark on the butterfly. In my case it needed to go on the top facing in.