Honda TRX 450 Cam Timing

We had an 08 TRX450 come in with low compression and not starting.
The trx450 have a decompression release on the cam that bumps the exhaust valve at start up.
Low compression on the electric start models are actually designed for easy starting. Once the engine starts the decompressor rotates around the outer gear of the cam and compression returns.
Root cause of this 4 wheeler not starting was tight intake valves. Both intake valves where open all the time.
After re shimming the valves all is back to normal.
Compression with valves in spec 30-40 PSI at starting. While running = unknown.
Compression is useless on this motor.
Leak down test is the only way to test for issues.(remember to put engine at TDC then rotate a few degrees to release decompression.

2015-01-06T23:03:41+00:00 By |Categories: Watercraft Service|Tags: , |Comments Off on Honda TRX 450 Cam Timing