Throttle stuck @4000rpm

[mikecap63]

Hi Folks

I'm just wondering if anyone with K100 has ever had an issue like my 85' is having right now?

[PGlaves]

I had a similar case once. It would increase RPM above about 3,500 but would not drop back below 3,500 to idle. It was caused by a small pebble blocking the idle stop screw from returning to its normal position. Check for something preventing the throttle plates from fully closing back to idle.

Otherwise, a serious air leak might cause a similar issue.

[GTRider]

Check the ends of the throttle cable to make sure they are properly seated in place, and be aware that a frayed cable can also get hung up.

Best,
DeVern

[98lee]

Mike,

Welcome to the Forum!

Since you are new to the Forum, I don’t know if you are new to your K100. With that in mind, make sure your choke is fully off (counter clockwise).

See if the throttle lock is causing the issue. Not all early Ks are equipped with the locking screw, but have the provision for it. It is a large screw or lever on the lower front side of where the throttle grip meets the front brake lever perch.

Look at the throttle linkage on the throttle bodies. See that it moves freely. See if it is returning all the way to the idle stop.

How long have you had the bike? When did you first notice the problem? Does it now ALWAYS do it? What was done to the bike between when it last worked properly and when this problem started?

Give us a bit more background.

Let us know what you find and we will let you know where to look next.

[hhshort]

I had a foam block in the fairing down by the injectors catch the throttle linkage. It occurred after a WOT run. Hairy event.

[ClassicVW]

I had this but on a Honda. Same 4,000 RPM. I was very lucky that it happened three blocks from my house. It was a bad throttle cable. I don’t recall if it was a bad end or a kink.