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EXUP servo motor humming

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WR250X history: Disconnected EXUP cables to install FMF Q4 muffler, later reconnected EXUP cables when re-installing stock muffler.

My EXUP servo motor seems to be operating when my ignition is on but the bike is not running. (Run switch position doesn't matter.) I can hear it humming. This occurs before starting the bike and after turning it off with the run switch.

The bike starts, idles, and runs fine.

It just seems wrong that the servo would make any noise with the ignition on and engine not running.

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Just a random question, but did you ride it offroad much, if any?

No. I dabbled a tiny bit when it was new. I do occassionally let a photographer borrow it at the racetrack and he does ride over bumpy, rocky terrain. I think's that what caused my low fuel light to start coming on at 70-80 miles instead of 90-100 miles.

Are you referring to this?


You have a bunch of ambient noise but I think I hear the same buzzing/ticking/humming I get from my EXUP.

I guess I'll put it in troubleshooting mode and adjust the cable slack.

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Cable #1 had a little slack. Tightened it while the ignition was on and the noise went away immediately.

Thanks. ๐Ÿ‘

Cool stuff. Sounds like it has a load sensor that gives it feedback...or is there a pos. sensor on the actual valve?

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