Ask the Editors: Vibrating Blaster Blues
2-strokes are known for excessive engine-induced vibration and the Yamaha Blaster is certainly no exception. Yamaha did attempt to remedy this by installing a counterbalance gear at the factory and excessive wear or faulty installation of this assembly is usually the culprit.
The place we would begin though would be to check the engine mounts to insure that the bolts haven’t loosened up over time. Once you are positive everything there is good and snug, it may be time to dig into the gear train (or have a professional if you doubt your abilities) to insure that the shaft and gear comprising the counterbalance assembly aren’t worn out. Believe it or not, a lot of racers actually remove this assembly entirely, deeming it as unnecessary weight. If you aren’t the original owner of the machine, it’s entirely possibly the counterbalancer is missing entirely.
The following video highlights what to look for:
[youtube https://www.youtube.com/watch?v=EHW3Av9KOgM&w=710&h=450]
If the engine mounts all check out and the counterbalance assembly is present and functioning properly, it’s possible this is just the nature of your 2-stroke. We have heard of success in mounting drilled rubber grommets between the frame and the rear plastic as well as between the seat and the frame to reduce the amount of engine vibration transferred to the rider.