50cc scooter cylinder kit is great for increasing overall performance on small underpowered 50cc GY6 QMB139 scooter engines.
Engine kit increases engine bore size from 50cc to 72cc and includes everything shown in the image; cylinder, rings, gaskets, roller weights, and more.
This kit also comes with the cylinder head and valves and is our most complete 50cc engine upgrade kit available.
This 72cc scooter engine kit increases low end acceleration as well as top speed.
This high performance scooter engine kit is easy to install. Combine with a high performance carburetor and high performance exhaust and get peak performance from your 50cc gas scooter.
Note: This high performance cylinder kit is only compatible with 4-stroke 50cc GY6 engines.