if you increase throttle easy tach works great but if your just going along and pin it the tach jumps up and needle fall back out of it down to about 4 grand until you let off engine doesnt bobble and runs fineany ideas stator,tach,etc
Just a guess, but have you taken the tack cable loose, on the left hand side of the snowmobile under the secondary clutch, and see if it's broken. If the cable is broken, it might do this.
