Crankshaft Bearings Polini MBK 51 (6302)

Crankshaft bearings for motorcycle, scooter and moped

Crankshaft bearings ensure the smooth operation of engines, whether on scooters, motorcycles or mopeds. The crankshaft is an integral part of the engine and the associated bearings and seals must be in perfect condition.

A crankshaft bearing set consists of ball bearings and oil seals. They are usually sold as a complete set and must be replaced each time the crankshaft is installed/re-installed.

What are the symptoms of defective crankshaft bearings?

The main symptoms of a defective crankshaft bearing are:

• Unusual metallic noises coming from the direction of the crankshaft.
• Unusual vibrations of the vehicle.

Defective bearings must be replaced immediately, otherwise there is risk of further damage to the engine. There are many different tools for crankshaft removal or bearing pullers.

You can see how to change crankshaft bearings in our crankshaft disassembly and assembly tutorial.