SELECTOR 688-45631-01 REC688-45631-00

Function and technical context

The 688-45631-01 selector is a steering and control component integrated into the hydraulic cooling circuit of Yamaha outboard motors. Its main function is to direct the flow of cooling water to the different areas of the engine according to the operating conditions, regulating the operating temperature and preventing overheating. This selector works within the cooling system, acting as a thermostatic valve that opens or closes the coolant passage depending on the thermal load of the propellant. Its correct operation is essential to maintain optimal temperatures, avoid internal corrosion in galleries and engine block, and guarantee the reliability of the propeller during prolonged navigation in different sea conditions.

When to replace this part?

Symptoms of wear or malfunction of the selector include erratic or unstable readings on the engine temperature gauge, accumulation of mineral deposits and rust that progressively block the passage of water, and gradual loss of effectiveness in thermal regulation that can lead to overheating. It is recommended to inspect this component during each seasonal inspection, especially if the engine has operated in brackish water, with high thermal load or after prolonged periods of non-use, since corrosion progresses silently. Replacing the selector preventatively before it becomes completely clogged prevents unexpected navigation stops and costly engine block repairs due to thermal damage.

Engine Compatibility Table

Equivalent manufacturer part numbers