×

Sale ends todayGet 30% off any course (excluding packages)

Ends in --- --- ---

11gram difference in pistons??

Practical Engine Building

Forum Posts

Courses

Blog

Tech Articles

Discussion and questions related to the course Practical Engine Building

= Resolved threads

Author
670 Views

I began to apply the piston balancing process to my v twin yamaha rebuild but immediately hit an curious issue. piston 1 weights: 450g, piston 2: 461g. they are factory pistons from a 70,000km engine. is it normal, is it safe, to remove 11gram from a piston?? thanks

I once had to remove 18 grams from the piston. It is doable as long as you know where it can be removed from. There is a webinar here with Andre demonstrateing the exact areas for piston weight removal.

That's a heck of a lot for a Japanese manufacturer, they're usually very close.

Are they the same bore size, might have had one cylinder bored out for a cheap 'fix' by a previous owner?

You may be able to mix and match the gudgeon (AKA piston, wrist) pin and connecting rods to better balance the reciprocating mass, well worth checking their mass as well?

We usually reply within 12hrs (often sooner)

Need Help?

Need help choosing a course?

Experiencing website difficulties?

Or need to contact us for any other reason?