Motobecane Polini 39mm Replacement Piston Letter:B Works in the older cast

Works in the older cast iron cylinders as well

Not the best for completely stock bikes unless you live somewhere flat

Pretty large opening on the mating surface so you'll have plenty of room to open up your intake

this is what you need

Athena's complete gasket set for Morini m01 and m02 engines

Motobecane Polini 39mm Replacement Piston Letter:B Works in the older castReplacement piston for 39mm MBK Polini av10 kits. Produced specially for us by an Italian manufacturer with 50 years experience. Some slight differences exist between these and the ASSO cast one that probably came with your Polini notice the lack of scallops on the side. Single ring! Choose your size! A= 38. 95 B= 38. 96 C= 38. 97 D= 38. 98