My timberwolf wants to freewheel downhill in gear unless throttle is applied.. any info please ?

 

your machine was built before engine braking was added. By increasing the throttle it makes the centrifical clutch engage but they disengage when the rpm drops. Sometimes by slightly advancing the throttle to engage the clutch then just holding it there will keep it engaged and slow the machine down. Try playing with it to get some limited engine braking.

 

But it should hold back in a lower gear. It doesn't clutch is disengaging

 

If my memory serves me right it is an auto clutch machine so it still has a centrifugal clutch to engage automatically when engine rpm reaches a certain level. Machines with engine braking have a special centrifugal clutch with spragues on them to engage at much lower rpm when decelerating. Perhaps someone with more specific knowledge could chime in here.

 

Yes, the centrifugal clutch on Yamahas has a one way clutch as a bearing. This keeps the drive engaged on the overrun, when the centrifugal one would have disengaged due to the engine revs dropping.