Cranshaft destruction

Hello folks

i first ride my rebuld PX and after just 100 kilometers i have destroy my new crankshaf on the clutch side (also the clutche is destroy too…)
does anyone had this kind of trouble with a brand new Mazzuccelli 60 mm cranck shaft for PX 200??

for me it’s a problem of heat treatment but what could it be if it’ snt?

thanks for your answer

I have seen this on a mazzuccelli crank before and I think it was a problem with the way the crank was machined. The taper the clutch sits on should have a radiused edge rather than a 90 degree angle. Also over tightening the clutch nut wont help.

Ouch that hurts dont it!

Yes an expensive lesson. I always use thread lock and tighten to 33lb/ft

Original von diablo: Yes an expensive lesson. I always use thread lock and tighten to 33lb/ft

200 euros to be precise…

thanks diablo !!

but i found the answer …i didn’t tight the clutch enought… so it destroy the shaft in the grow of the key…

mistake make learn sometime[:’(]