input noted... I will try the stock muffler again with the 13x8... its leaking at moment... so I don't use it... the 128 was with BCM pitts muffler btw... made enough RPM's... only recently have I tried the rossi... the stock one I must fix the leak and then also try it again... I only had 2 runs with the 12x8 and rossi and the engine is still really new... so I would be disappointed if the bearings are already failing...