Scooter repair guidebook

High RPM but low speed in scooter - reasons & solutions.

If the scooter have high rpm but low torque & power, here you can find a perfect solution.

In this post, you can find one quick dirty fix along with detailed instructions on how to permanently fix high rpm low power issue in all scooters.

If everything else(meaning engine starts, tire turns at low rpm) is working fine, the reason is most likely something to do with the CVT pulley system.

Most common reasons are worn out belt, worn out rollers, cone or sometimes, damaged springs.

Quick & temporary fix using ‘grease & sand paper method’ - not spending money.

If the scooter is too old, and you don’t want to spend any money on it, you can try this as a temporary fix.

First open the CVT cover and remove both driven and driving pulley.

Driving pulley variator - image.

This part of the system have grease inside to allow cones to move smoothly. When grease is dried out, it limits the smooth movement of the pulley system. This along with worn out rollers will substantially reduce the torque and power of the scooter.

So remove every part of CVT pulley system and remove rust, rubber particles, and oil. Then apply grease to where it is needed.

Driven pulley and clutch - image.

You can scratch or sand the surface of the clutch that claps. Remove any rust or dirt from the clutch. This will allow better grip and improve the performance of the scooter.

High RPM but low speed in scooter - permanent fixes.

Change the belt.

Thin belts are the most common reason for the low torque & power. But changing belt only without changing other parts often gives weird(not optimal overall) results, but it fixes this problem.

When the belt is worn out it will take very high rpm to get the scooter moving.

This is the telltale sign of a worn out belt.

This also means you will be getting very low torque & power at high rpm too.

Change the rollers.

Rollers are inside the variator and helps to decrease the gear ratio, when centrifugal force(rpm) is increased.

When the rollers are worn out or sometimes chipped, the gear ratio will remain the same even at high rpm. Changing the rollers will help solve this problem.

Change the CVT pulley system.

Sometimes if the scooter is too old, most of the parts becomes obsolete, and you need to replace the CVT pulley system altogether.

Changing the CVT pulley system altogether will give the best optimized results. Everything will work synched & great again in no time.

Change the spring - clutch not clamping.

Clutch at the driven pulley side not clamping/slipping to the wheel shaft is another reason for the low torque & power with high rpm.

A quick fix is scratching the clamps on the clutch plate using sand paper. Sometimes the spring breaks and you need to replace it.

If weird sounds are coming from the back side of the scooter, it means the spring is broken. Replace the spring and clamps and everything will work fine.

Change the pulley cones.

Pulley cones in the driven pulley and driving pulley may get worn out after long years of using. This can be solved by replacing it with a new one.

When changing the cones it is recommended to also change rollers, belt and springs.