My sea pump squeals when I fire the boat up for a few seconds then stops. It actually only does it when its cold and I give it some gas to help it stay running when I launch it. After it warms up its good, but then I notice it sqealing again around 3k rpms. Its been doing this for a while but just notice that my temp is going from 160 to 180 when it squeals. The belt is snug and last night I tried to snug it some more but its already tight.

Shoul my next step be replacing it?

I would take the belt off and spin the idler and pump pulley's by hand to make sure the bearing's are not trying to seize . If the belt is tight it should NOT be sqealing under normal circumstances , tells me something is amiss !!

Like said above, might be the sea pump bearing. The parts to rebuild them are cheap compared to the pump itself, all you need is a press and some time, cost me about 100$ to rebuild mine, that price did not include a new shaft.

There isn't a idler pulley, the belt goes from the pump to the crank. Both sea pump and circulating pump was rebuilt last year. I'll try spinning it by hand.

Come to think of it, it squealed last year after having the work done. I just assumed it was because the belt was cold and needed to warm up. It was only when the temp jumped up that I put 2 and 2 together. I guess I can call the dude back that rebuilt them.

Funny thing is it was done about the same time last year.

Its a Mark IV engine with Vbelt. The pump will not spin by hand unless you remove the impeller. If was rebuilt last year, I would try the simple remedy first. Change the belt and make sure it’s TIGHT.

therer are only 2 places it can be tightened, right?

I always tighten mine with a pry bar and some common sense to not make it so tight that it destroys the pump or belt. There is a decent amount of load on it when its pumping water.

I see a bolt right above the pulley and 1 just to the right of the crank which i believe is where it can be tightened. I'm hoping for a bad belt, the pumps dont look fun replacing.