My throttle has been extra jumpy during decel lately. The sensation is as if the throttle plates slam shut in two separate throttle positions as the twist grip is turned toward closed. When I had the same problem one year ago, I actually pulled the air cleaner and viewed the throttle plates. As I turned the grip toward closed, the plates would suddenly snap toward closed then re-open well before I had the grip completely returned (also well before any free play). I did not document the solution, so, now that the symptoms have returned 1 year later, away we go! The procedure involves moving the throttle sensor -the one that reads throttle body position- repeatly from stop to stop to re-establish a consisently good contact path inside the sensor.
Tools: Torx T20 security bit. Make sure the bit is short enough to clear the brake lines mounted against the frame.
Linkage access cover: Three Torx bolts of varying length. Raise the fuel tank for access.
Linkage:
Start of rotation: Make sure the key is off, or you will be fighting the servo motor.
End of rotation: Go through this cycle many times rapidly.
As a bonus, I sprayed oil into these lube holes at the end of the shaft, RH side:
Why not just put it in a higher gear and go to WFO several times, you ask? That helps but the 'fix' it doesn't last for longer than a day or two. The movement will be slower using the twist grip, and I don't think anyone really wants to put undue strain on the engine by snapping the throttle from stop to stop, several times in a row while it's running, regardless of the selected gear and RPM. Also, stop-to-stop movent is not possible via the grip with engine off and key on. You only get a very small movement (maybe about 5% deflection). The most effective and long-lasting way is to use rapid, repeated stop-to-stop movement via the method I've shown. My throttle control is as smooth as glass (comparatively) now. The fix should last the rest of the season, as it did last year.
Tools: Torx T20 security bit. Make sure the bit is short enough to clear the brake lines mounted against the frame.
Linkage access cover: Three Torx bolts of varying length. Raise the fuel tank for access.
Linkage:
Start of rotation: Make sure the key is off, or you will be fighting the servo motor.
End of rotation: Go through this cycle many times rapidly.
As a bonus, I sprayed oil into these lube holes at the end of the shaft, RH side:
Why not just put it in a higher gear and go to WFO several times, you ask? That helps but the 'fix' it doesn't last for longer than a day or two. The movement will be slower using the twist grip, and I don't think anyone really wants to put undue strain on the engine by snapping the throttle from stop to stop, several times in a row while it's running, regardless of the selected gear and RPM. Also, stop-to-stop movent is not possible via the grip with engine off and key on. You only get a very small movement (maybe about 5% deflection). The most effective and long-lasting way is to use rapid, repeated stop-to-stop movement via the method I've shown. My throttle control is as smooth as glass (comparatively) now. The fix should last the rest of the season, as it did last year.