Reply To: My Mercury Runs Hot?

[need2fish]

The telltale stream should be warm but not enough to scald you.

If it is really hot, it’s possible the old impeller had lost bits of its vanes, which are now lodged in the cooling system somewhere. At idle enough water passes through to cool the engine, but not enough to do it at high speed.

Another possible cause is the water tube seal where the tube enters the powerhead is damaged or missing.