IS THE POLINI BOLT PATTERN THE SAME AS BZM ON THE CRANKCASE? IF ANYONE KNOW?

pretty sure that the cranks are the same as in width & thread so you can use either in your engine

im pretty sure there diffrent according to glen

NO ! there is a bzm head for the polini and a bzm head for the bzm crankcases. they are a totally different bolt pattern.

i got the 620 cases and they wouldnt fit my barrell

they are out by a fair bit. probably 10mm in all directions.

aside from that they are pretty well the same. the clutch housing and pullstart still bolts on.

well there you go 100%, i was referring to the cranks but yeah the barrels have a different bolt patern grevs has the polini bottom end with a BZM barrel

ok thanks , i was thinking of getting an OR barrel but they are the bzm bolt patern , oh well guess i will end up getting a bzm barrel in time to come