Piston, Cylinder, Head Maintenance - Vittorazi Motors COSMOS 300 Maintenance Manual

3.14.2 Piston, cylinder, head maintenance

Do not use abrasive tools and corrosive liquids that may damage the surface.
Carefully remove gasket residues from the cylinder and the crankcase.
Thoroughly clean the piston crown, the piston grooves, the exhaust port on the cylinder and
internal surface of head.
Clean only the 2 decompression holes on the cylinder with a 3 mm drill bit, taking great care.
Immerse the piston, cylinder and head in an ultrasonic bath containing cleaning liquid for
aluminum.
The cylinder and piston belong to different selection classes according to tolerance.
Check the selection class engraved on the piston.
Measure the diameter of the piston 10 mm from the base of the shell.
Measure the diameter of the cylinder 10 mm from the top.
Cosmos 300 – Maintenance manual – V2 171