Overheating Mercury 250 Optimax DFI

[jnj]

We recently purchased a Polaris EX2100 (2004) w/a Mercury 250 Optimax DFI V6. The warning system sounded for overheating. We flushed the cooling system and cleared debris from the propeller. It still heats up??? Note: The lake water is filled with grass. We've been driving it for two months and have to continually pull grass out of the propeller underneath the boat. Afterwards it runs full speed but then begins to heat up again. ???

 

[tlh 178]

could be thermostats, popet valve or water pump needs service. could be something as a small snail or rock in one of your cooling hoses. when was the last time engine had service work done?

 

[SkiDad]

You need to change the impeller when you buy a boat from someone. You don't know how old it is. You should replace every 3 years. Part is approx 30 bucks and can b done in under 1 hour. You might need a helper to help with the lifting of the lower unit as that is a big one. Tipping up the engine makes this easier to do. There are videos on youtube.

 

[Faztbullet]

This is a sportjet, check the intake when on trailer for blockages and the poppet valve for debris. Fix this quick as if engine is not cooling so is the compressor and it will fail from overheating.$$$$$$$