CRANKSHAFT 3 PART 66T-11432-00

Function and technical context

The crankshaft is the fundamental component of the power transmission system in Yamaha engines, responsible for converting the reciprocating movement of the pistons into continuous rotation. This part works inside the engine block, subject to extreme mechanical forces generated by combustion and acceleration of the driving fluid. A worn or damaged crankshaft compromises proper engine alignment, causes excessive vibration, loss of compression and can lead to chain failures of other components such as bearings, valves and the transmission.

When to replace this part?

Symptoms of crankshaft deterioration include abnormal vibration of the engine running, metallic noise coming from the crankcase, progressive loss of power and increased fuel consumption. Although the crankshaft has a very long life under normal maintenance conditions, it should be inspected regularly if the engine has a history of overheating, contact with salt water without adequate dealloying, or is frequently operated at maximum rpm. Preventive replacement of the crankshaft in heavily used boats avoids costly repairs and unexpected stops while sailing.

Equivalent manufacturer part numbers