The growing automotive world demands change for better transportation, not only on fuel-efficient engines but also on the comfort level of driving. One of them is a change in the transmission system. The purpose of this Final Project is to know the working principle, troubleshooting and the influence of variations of CVT roller weight on Suzuki Nex-FI 2014 motorcycle. This research process is done by analyzing the measurement result of each CVT component and then the result of the measurement will be compared with standard size to know the feasibility of the component. In addition, this study also conducted variations of CVT roller weight testing, after roller replacement is expected to improve the performance of 4-step fuel motor. The research method used is the experimental method that is by holding the throttle at 3250 rpm after stable then throttle spontaneously rotated up to 10000 rpm. From the measurement analysis results, the belt drive is worn from standard sizes of 19.50 mm to 18.00 mm and a tolerance limit of 18.60 mm. As for the results of roller variation testing, if using a lighter weight roller for example 8 grams and 9 grams then obtained results more leverage at low and medium rotary speed, compared to using roller 11 grams (standard). The weakness of the 8 gram and a 9-gram roller is only getting good acceleration and torque at low speed only. While at a high rotational speed less than the maximum. If using 11 grams roller (standard) then acceleration and torque will get less than maximum results, but get maximum power.