Yamaha Zuma 125 modded out to 192cc. This is my sleeper Zuma Asia conversion. Like Jeeps, there are many esthetic modifications for the Yamaha Zuma/BWS - we all choose what we like. I live in the Desert, so Sandcolor fits the surrounding area.
The upgrade requires the entire breakdown of the stock engine, and boring out/modification is necessary on the engine to accept the larger piston.
I did not change my stroke or my crank. This is running with the stock crank and rod. The piston size was all that was changed. "big bore"
Top Speed: 65mph - With maximum low-end torque. The top speed is not as important to me in traffic as torque is, to very quickly accelarate to move around traffic. How often do you do 65mph on an inter-city road?
Want more top speed? The top-speed of the Zuma is not controlled by the engine rpm but rather a gear-drive rpm. That can be changed with a new final drive gear. Like all gearing, changing the number of teeth will enhance the rotations the gear can make. This can get you to 80+ mph on a Zuma, but you will give up take-off speed (torque) for top speed.