30+ Overheating- Solution in Hand?

[Frank Langer]

Coming back to this issue even though consensus says overloading engine is source of overheating. When motoring at WOT I can push 200 degrees before I chicken out and back it down. Takes a long time (10 minutes) to cool down to normal temps (~170). I can motor for hours at 2200 rpm with temps at 170. Cooling water flow looks like this:

Does that look like adequate cooling flow at speed? If not I might look into a new freshwater pump. Or maybe I need a new coolant pump? Or both…

Hi Doug,
I think motoring at 2200 rpms and temp of 170 degrees sounds right. If I recall correctly you have the 5411 engine, while mine is the 5416, slightly larger. Your engine exhaust looks a bit less water flow than mine, but that could be difference in engines and I recently replaced the raw water pump. Yours does not look too low to me. Just my opinion...
Frank

 

[Christian Williams]

That looks like plenty of water to me. More than my system puts out.

 

[bigd14]

Thank you both. It's a bit hard to tell with hardly any other inboard engine sailboats around me. Frank, its the M18 engine, 14hp. Which I feel is a little underpowered for the size of the boat, especially when dealing with the strong river currents we get around here. This is one reason I feel like getting to the bottom of the WOT overheating situation, there are some times we need all the power we can get!

 

[Frank Langer]

Thank you both. It's a bit hard to tell with hardly any other inboard engine sailboats around me. Frank, its the M18 engine, 14hp. Which I feel is a little underpowered for the size of the boat, especially when dealing with the strong river currents we get around here. This is one reason I feel like getting to the bottom of the WOT overheating situation, there are some times we need all the power we can get!

Yes, Doug, I remember your engine. Mine is the 5416/M20 16 hp. which I also find barely enough power in a strong chop against the wind.
Frank

 

[L-G Harvey]

Sorry, I'm a bit late to this discussion.

Waterflow in the video looks similar to mine (although I have a 5416) and I have no overheating problems. However, I had a very similar problem a few years ago which was solved by a thermostat replacement.

Just a thought...

Louis

 

[bigd14]

Thanks Louis, I’ll put in a spare thermostat soon and see what happens.