Naraku V.2 90cc cylinder and head kit for Chinese GY6 50cc scooters.

The V.2 version has had improvements to the piston design and compression ratio; the molybdenum coated piston has two additional CNC'd oil groves to help lubrication and improve the life of the cylinder, the compression ratio has been achieved with the 50mm combustion chamber of the included head. The head included has bigger valves and matched ports for increased power.

The cylinder bore has been machined to 52.4mm, whilst keeping skirt the same outer diameter, meaning machining of the crankcase is usually not required. 

The main jet, variator and clutch must be adjusted!

This is only suitable for GY6 139QMB 50cc engines.

Naraku NK100.52