Running Hot-Then not

[azirish77]

I just took out my boat for the first time of the season after getting the impeller changed. When I dropped the boat in the water, the engine started right up. After idiling for a few minutes, I noticed that it was running pretty hot.(About 200) It then sputtered a little bit, backfired, and cut off. I let it cool and attempted to start again. It started after a few minutes, but continued to run hot. I then shut it down and let it sit for an hour or so. After an hour, I started it back up so that I could take it to the trailer. It started right up and I made my way back to the ramp. The gauge was now reading about 160 degrees. It ended up running fine all weekend. My question is...
Is it normal to run hot after sitting for 6 months and putting in a new impeller?
Is it possible that something was sucked in and eventually passed through?

Thanks for all of your help

 

[Bondo]

Re: Running Hot-Then not

Is it normal to run hot after sitting for 6 months and putting in a new impeller?

Nope,... And it's Doubtful it passed a blockage...

 

[azirish77]

Re: Running Hot-Then not

I didnt think it could pass something. Any suggestions on what it could have been? Could there have been an air bubble?

 

[Bondo]

Re: Running Hot-Then not

Could there have been an air bubble?

Ayuh,.. Again,.. Extremely Doubtful...
I'd sooner think there's still some debris floatin' around somewhere...
It could be some old impeller vanes stuck in the P/S Cooler, if so equiped..

 

[azirish77]

Re: Running Hot-Then not

Thanks for the help. What would you recommend as your next step? I dont know much about engines, (as you can probably tell). Should I take it to have it looked at, or should I wait until it runs hot again? It ran great for 2+ days after initially running hot. However, I would obviously hate to do more damage....

 

[T-Bone Coug]

Re: Running Hot-Then not

Take it to have it looked at. The possibility of a blockage could cause engine damage next time you go out. Debris in the cooling passages is too unpredictable to take out on the water, even for short periods of time.

 

[grahamh]

Re: Running Hot-Then not

Could also be a sticky thermostat that's not opening. I've seen it happen on cars, so I would think it could happen on a boat too. Might be worth checking out.

 

[SeanMcl]

Re: Running Hot-Then not

Could also be a sticky thermostat that's not opening. I've seen it happen on cars, so I would think it could happen on a boat too. Might be worth checking out.

I add my vote for this. Pop it out and drop it in a pot of boiling water, see if it opened up, remove, cool, and repeat a couple times. The thermostat is a regular automotive type, it's nothing special.