The motor I'm using now is a 10mm DM with smaller bore 74.50mm. 557cc 135hp.
DM cylinders come with a 78mm bore. But I wanted to use a Max Z sled piston.
Piston weighs 250 grams after intake & oil holes mods.
78mm piston weighs 314 grams.
The 10mm motor rev's faster & rev's higher with the Max Z piston.