Just finished rebuilding my brothers blaster. Top end only as the bottom end looked perfect. No play or damage anywhere. After doing heatcycles i test rode it and noticed a good bit of vibration that seems to be coming from the top of the motor. I checked counterbalancer gears to make sure the little o,s were lined up. Checked all mounts, oil level is good. Everything seems to check out so far. I installed a ken oconer rechambered head and removed the rubber pieces. Could this be it