1976 yz400 piston ?

[TT5 Matt]

piston pin location has all to do with where the transfer ports are located and nothing to do with rod length or stroke of an engine

[motomaniac]

piston pin location has all to do with where the transfer ports are located and nothing to do with rod length or stroke of an engine

yes but the gudgeon pin is wider than the bridge between the transfers so moving it a little one way or the other makes fug all difference.

[ozyditcher]

I got my piston today. Not the same, pin location is off.

Then its not 75/76 , they offset the gudgeon as a measure to help seizures on the exhaust port . No matter the motor runs the same with either

   MY PISTON I TOOK OUT HAS 51004 ON IT . THE MX400 PISTON HAS 51003.

[motomaniac]

Do us all a favour mate and call Wiseco to recalland remake all their #232MO8500 pistons that they have had  listed for the 75/76 Yamaha mx/yz400 for nearly 40 years. Ta .

[DCPlasticsguy]

Wossner sells a piston for the 1975 MX 400. However, they don't list it for the YZ 400. They offer 85, 85.5, 86 and 86.5. Retail is $145. We are set up as a dealer with them as well.