BMWMCCWA

Hi, does anybody know if the right and left pistons are the same on a R75/5, or are they different?
If they are different how can I tell them apart, as both my pistons are exactly the same, and both without any markings indicating right or left.
Only one has an arrow and the word (vorn) on the crown.

I hope somebody can help.

Dieter

Dieter

I think Vorn in German means in front. That being the case you will notice 1 cylinder sits slightly forward of the other hence "in front".
Well that would be my guess but take note it is not based on technical knowledge or experience.

Cheers
JonO

This one is a beauty.I had to check. THe inlet valve pockets are slightly bigger, so you can tell. So when the pistons are fitted, one gudgeon pin is slightly lower and the opposite one's gudgeon pin slightly higher than mid point...........John

Yeah Jono, you're right about the vorn being front, but the left pot is a good 2 inches ahead of the right pot on account of the left conrod being on its own journal, downstream of the right conrod. That's why the bikes jiggle at low speeds/rpm. Dieter is missing a complete direction arrow on the crown of one of his pistons.
John

Thank you every one, I think the larger pocket for the inlet valve is the best way to check and I will do this tomorrow.

Thanks again for your help

Dieter