Gy6 performance parts, high performance Gy6, GY6 4-Stroke Engine Performance Parts, mod kits for gas scooters,gy6 engine,gy6, strada performance, vento performance, scooter performance, scooter performance upgrade, 150cc performance Performance Roller Weight For replacement of 16mm x 13mm rollers. Available in 3 to 6 gram weights. These will work with GY6 engines found in the Chinese scooters using this size weight. Most units with a Chinese GY6 engine can be altered for improved acceleration with weight tuning.