1990 90 Pissing hot

[hiflutin]

Have a 1990 90 hp that I was getting a Overheat alarm at a higher RPM.
The Impeller is new.
Have taken the Thermostat out-(Plan on getting a new one)
& the motor is Pissin Hot
What else to check?

[ausnoelm]

pretty common for them to over heat at high RPM (over 4,000) it is caused by blockages in the water passages, they are quite small in a yamaha and get blocked easily, you will need to remove every cover you can find to clean them, and the head too.

[99yam40]

never take out stats and run it will cause problems with circulation