PIÑON 61N-45551-00 PAF25-04000005

Function and technical context

The 61N-45551-00 sprocket is a critical component of the power transmission system in Yamaha F25 series engines. This gear is part of the gear train that transmits the rotation of the crankshaft to the propulsion system, ensuring that the force generated in combustion is efficiently transferred to the propeller. Its correct operation is essential to maintain the response of the engine and the propulsion capacity of the boat, since any wear or deterioration in its teeth can cause loss of traction, abnormal vibrations and, in extreme cases, partial blockage of the transmission system.

When to replace this part?

The transmission sprockets show progressive wear when gear noises (buzzing or clicking during acceleration), abnormal engine vibration in cruising speed, or perceptible loss of propulsion power at maximum revolutions are observed. It is recommended to visually inspect the condition of the tines at each seasonal maintenance check, especially if the boat has been hit or navigated in silty waters. Preventive replacement of this sprocket prevents cascading damage to the rest of the drive system, which would result in significantly more expensive repairs.

Equivalent manufacturer part numbers