The overly long piston design causes inevitable piston base skirt to cylinder direct metal to metal contact with the current rubber ring position & lack of constant cylinder lubrication arrangement..A factory provided cylinder mid-length positioned drip oiller combined with a Single rubber o-ring at both piston ends would clearance isolate any metallic piston-cylinder scaring & have perfect assured lube viscosity without overly heavy fuel-lube mix ratio exhaust mess...tom.