[tdmaker]

1998 Talari with a 350 Magnum engine. Last two times I've had my boat out the engine hasn't got any temperature in the engine. If I'd shut it off and sit for a while the temp gauge would slowly creep up to around 140°. But as soon as I'd start it, it'd slowly creep back down to no temperature. So I assumed it was a stuck thermostat. I've replaced it with an automotive 160° thermostat(same temp as original), the only difference I see in the two being a small vent hole on the automotive thermostat that was not in the original that I'm replacing. I haven't had it in the water yet, just started in my driveway with muffs on it. It will reach 170° but will quickly drop back down to zero when the thermostat opens. So is it ok to have a thermostat with a vent hole in it? I've done some searching and most forums say yes, to help break up air pockets. Or is it common for the temps to be erratic while idling in a driveway connected to my garden hose?

Thanks for any info.

[tdmaker]

Well I figured out my problem. My main problem was myself. I replaced the thermostat in the wrong order this spring. Inside the water neck first gets a cork gasket, then the thermostat, then the plastic spacer. I had the order reversed. And yes an automotive thermostat is different than a marine thermostat, and so is the water neck gasket. It has brass pieces in it to ground the filler neck so temperature sending units will work.


Sent from my iPhone using Tapatalk

[Clv1]

Thanks for your post!

[Zins]

Hey, Thanks for posting your fix!! In the fall as I winterrise the RV and the boat, it all starts to blend. So, I did the same thing, and have been thinking it was going to be a first, and take the boat to the dealer...so, flip the thermostat to the top, and back in business!!

[cswinings]

Originally Posted by tdmaker

Well I figured out my problem. My main problem was myself. I replaced the thermostat in the wrong order this spring. Inside the water neck first gets a cork gasket, then the thermostat, then the plastic spacer. I had the order reversed. And yes an automotive thermostat is different than a marine thermostat, and so is the water neck gasket. It has brass pieces in it to ground the filler neck so temperature sending units will work.


Sent from my iPhone using Tapatalk

I did the same thing when I replaced my thermostat last year. I put the thermostat right on top of the manifold instead of on top of the spacer. Soon as I switched started getting better temp readings.