I bought a blown up banshee a few yrs back.. rebuilt it with all new parts.. and it ticked.. i've replaced everything I thought it could be.. Reeds, oustide crank bearings, all new topend. port chamfers, transmission bearings, water pump bearings everything seems ok.. all clearances are in check also... i've had the motor split 3 times looking for problems. but ikeep coming up with nothing... so... I'm just running it till/if it blows.. then I'll know what the problem is! lol
I'm thinking it might be a center bearing on the crank.. It spun freely last time I checked the crank so when we tear it down for the 4mil this winter I'll go through and dbl check everything again.. but I dont think i'm gonna find anything again lol