risers/T-stat question

[Jono]

My boat runs a perfect 160* all the time. When I shut it down, the temp guage rises 10 or 15 degrees. But once underway again, it drops back down to 160 again. I'm just wondering if this is normal. Being a 1996 model, I've been wondering if i'm on borrowed time with the risers. With the boat running, I can hold my hand on the top of the riser for maybe a second or two before I pull away.

[DanielC]

That is normal. When you stop the engine, you also stop the cooling flow of water, and air. With no cooling water flow, the temperature of the water in the engine will go up.
Your car does this too. Ever been standing by a car, and after it sits for a minute or two, with the engine off, and doors locked, and nobody in it, heard the electric radiator fan come on?

[AirTool]

Your car does this too. Ever been standing by a car, and after it sits for a minute or two, with the engine off, and doors locked, and nobody in it, heard the electric radiator fan come on?

Or in the old days without an overflow bottle ...and in about three minutes a big burp of green stuff on the ground.