CIGúEÑAL 1 PART YAMAHA 66T-11412-00

Function and technical context

The crankshaft is the fundamental component of the power transmission system in Yamaha engines, responsible for converting the linear movement of the pistons into continuous rotation of the drive shaft. It works inside the engine block, supporting the explosion forces of the combustion chamber and transferring this energy to the engine output shaft. Its structural integrity is critical: a worn or cracked crankshaft generates excessive vibration, misalignment of the propulsion system and, in extreme cases, complete engine shutdown while sailing.

When to replace this part?

The crankshaft requires visual inspection at each annual maintenance check, paying attention to signs of corrosion, microcracking or deformation in the support journals. Although it is a long-lasting part in marine petrol engines, symptoms such as abnormal vibration during acceleration, deep metallic noises in the crankcase or progressive loss of power may indicate advanced wear in the support bearings or non-visible microcracks. Preventive replacement in case of detected damage avoids costly emergency repairs at sea and ensures the reliability of the propulsion system.

Equivalent manufacturer part numbers