Hoca Roller Weights for 50cc 4-stroke QMB139 engines. The QMB139 is the most popular 50cc 4-stroke engine found on Chinese scooters.
We recommend starting performance upgrades by changing the variator roller weights first.
Heavier roller weights= A slower take off speed with more acceleration and a higher top speed. Lighter roller weights = A faster take off speed with less acceleration and lower top speed.
