Home › Forum › Ask A Member › 15hp exhaust & water leak…why? › Re: 15hp exhaust & water leak…why?
Turns out it was A-OK, but the motor couldn’t pull enough water through at idle or low RPM in a test tank. On the boat, totally fine. In the test tank, at mid to high range, the cooling system worked fine.
I’m still wondering why this was going on because I tore the whole motor apart looking for the smoking gun, but I didn’t find anything. I double and triple checked all water passages, and what made me question things is because I had just worked on another motor of the same model year a week previous and it pumped water at idle like a water hose.
I’m writing this off to the inconsistent quality of the ’74-76 models. Not sure how a motor can run under load on my boat at WOT for 5 mins straight and run cold by all accounts (120° at the top of the cylinders, cylinder head 115-125°), but overheat progressively in my barrel at idle. And it pumped like a hose when underway at mid to high range, but basically just the ‘mist’ you mentioned at idle or in neutral.
Recently had a customer bring in a ’74 evinrude, and it is obvious it has some of the ‘upgrade/recall’ kits installed (different cylinder head that is primer red). Motor starts on 3 pulls dry/cold, but it’s dying off with anything over idle.