Re: 1969 evinrude overheating at high rpm
Did you replace the whole water pump, or just the impeller?<br />Is there a chance that exhaust is getting under the base of the water pump and into the cooling system? Or perhaps through a crack in the casting along the aft end of the 'tower' on which the water pump sits, letting exhaust in that way?<br />Did you use sealant between the impeller wear plate (stainless) and the exhaust housing? Was the pump and impeller the same as the one you switched out?<br /><br />Since reving the engine up in neutral is a quick way of destroying it, I assume you're testing this on the boat at speed. Where is the anti-ventilation (cavitation) plate relitive to the bottom of the boat? 1 or 2 inches below it?<br /><br />How did it work before you changed the waterpump?<br /><br />Please forgive all the questions!
