Hey, new here.

I just picked up a model 85 Alpina 250 and found out the piston was a 76mm. Anybody ever seen this? Seems like a huge jump from 72mm. The piston was cracked when I got it. Anybody know where I can get another one?

 

thanks in advance. 

Hullo J,  Try France trials Classic, they are on Rheims, east of Paris. I am sure I have seen a 76 mm piston on their lists. This big bore conversion brings the cc up to 272 .  Incidentally, the 290 Sherlock is the same 272 cc !  Let us know how you get on. 

Predictive text, always good for a laugh  !  That should have been Sherco, 

If you struggle to get anything, the MZ301 is 76mm and has plenty of metal in it so can usually be modified to suit. The genuine ones are really good quality too.