Yamaha BWS 125cc engine rebuild

This Yamaha BWS 125 was brought into us as a non runner, the customer stated that as he was riding the scooter it started to loose power and eventually the scooter stopped altogether.

Badly worn piston (due to lack of lubrication)
Badly worn piston (due to lack of lubrication)

Straight away we realised that the engine was very low on compression as the engine was turning over, we confirmed this by removing the spark plug and carring out a compression test.

We then drained the engine oil, minimal amount came out indicating that the lack of compression was possibly down to lack of lubrication to the top end of the engine.

Scored engine cylinder
Scored engine cylinder

We then removed the engine cylinder head, cylinder and piston and found the damage as can be seen in the photos! As suspected this had been caused by a lack of lubrication due to the engine oil level being so low. A new cylinder/piston kit was sourced, fitted and the scooter was also given a good service.

Our customer was very pleased to have his scooter back however this could have potentially been avoided with regular maintenance.

 

Any queries regarding scooter or motorcycle servicing please call us on 01759 307770