How hot?

[suparslinc]

87 305 mercruiser. Just got some issues resolved today, hooked up the hose and started it up. I wanted to let it reach full operating temperature so I had an idea where that was, well when the gauge got up to ~200F I chickened out and shut her down. That seems like it's getting a little on the hot side to me.

I believe the impeller was working because I had water pouring out the petcocks in the bottom of the block at first. But I saw that immediately, shut it down and closed them. So how hot am I supposed to be running?

 

[Bondo]

Re: How hot?

Ayuh,....

About 160?......

I'd start with the Impeller.....

 

[suparslinc]

Re: How hot?

Know whats funny? After screwing around with it for a couple more hours with same results, I gave it a little throttle. The temp gauge dropped like a rock to ~175. I wonder if the impeller wasn't spinning fast enough at idle to pull fresh water.

 

[Don S]

Re: How hot?

It's a rubber impeller and the vanes are probably bent over due to lack of being replaced when they should have been. Evey other year is recommended time for impeller replacement.

 

[suparslinc]

Re: How hot?

I've heard that. Can't remember if the guy who sold it to me said they were replaced or not; looked at a couple boats and what I was told runs together. I'll have to do that this summer don't want to burn the engine up.