M 3418098.A0: Malossi Piston 63.0 A0 for Alum. MHR Kits
This is the first over for Malossi aluminum MHR 177/187 kits. With aluminum kits after the piston has been run long enough to have lower than decent compression and the cylinder has not been damage you can upgrade to the next over piston. With the aluminum cylinder the piston are very slightly larger and don't require an overbore of the cylinder. A standard cylinder is labeled as a 0 and when it's worn you upgrade to an A piston and when it's worn you upgrade to a B and so on.
This is the first over for Malossi aluminum MHR 177/187 kits. With aluminum kits after the piston has been run long enough to have lower than decent compression and the cylinder has not been damage you can upgrade to the next over piston. With the aluminum cylinder the piston are very slightly larger and don't require an overbore of the cylinder. A standard cylinder is labeled as a 0 and when it's worn you upgrade to an A piston and when it's worn you upgrade to a B and so on.