6 cylinder mercruiser opperating temps ??

[twintrades]

I have a 79' mark twain I/o with a 165 hp 6 cyclinder mecruiser engine.

We were out tubing and sking today( well tring to ski and kneeboard)

The engine would get around 190+ degrees Is this normal ?? It was alot of pulling ( one tube) And starting/stoping, slow driving with me learning how to suck at kneeboard and skiing.

When i was done i saw the heat at 190-200 ish then we drove to a beach and had lunch. While druving the boat engine cooled off to a normal temp.

So is that normal to have the engine gett hotter durring thoses activitys. When its in nutral its fine also.

 

[Bt Doctur]

Re: 6 cylinder mercruiser opperating temps ??

NO, not with a 145 deg. thermostat impeller, water pump, riser clog, manifold clog are prime culprits

 

[twintrades]

Re: 6 cylinder mercruiser opperating temps ??

Just thought it was weired how the system recoverd after we were done towing. And its fine at dock in nutral.

Well ill have to take it out tomorrow and figure out whats up. IN the mean time anyone else can chime in and give me ther POV

 

[achris]

Re: 6 cylinder mercruiser opperating temps ??

What revs do you pull at WOT? Should be 3900-4300. All the manufacturers recommend that you drop a prop size when doing tow sports. If your current prop is only allowing you into the lower end of the WOT range, then towing skis/kneeboards will push the engine into 'overload', and easily explain the higher temperature.

If you want to engage in any form of tow sport again in the future you may need to change to a smaller prop...

Chris.........