35 cooling

On my 3.5 I have always been s

On my 3.5 I have always been suspicious about its cooling. It is only one year old. The water always runs freely out the tube but it never has given off any heat. On one occasion it over heated and blew the oil plug. Nissan tried to say that it was due too a plastic bag covering the inlet. What ever! ( by the way that was false. The water was running out the tube when it blew the plug.) However I have discovered that if I let the engine come to a total idle after running it that very hot water does start too exit the tube and continues as long as the engine stays at idle. There is very little difference between the amount of water exiting the tube at idle or run speed. Why then won't the thermostat allow the water too pass through it at running speed?

"Why then won't the th

"Why then won't the thermostat allow the water too pass through it at running speed?" Huh? What makes you think that it isn't?

Since I have not taken this th

Since I have not taken this thing apart I do not really know how it is constructed. However my guess is that there is a bypass that allows the water to exit when the thermostat is closed. The reason I say that is because water comes out when it is first started and cold. However the water coming out at first never gets any hotter no matter how long it is run or how hard. The only time the water gets hot is if I disengage the prop and let it idle. Then it comes out very hot. Almost steam. This has been going on from the beginning when I first bought it.
I quite dealing with this under warranty since it is clear that they do not want to honor the warranty correctly and fix the problem. They make constant excuses and bogas repairs that never have fixed the real problem. I simply would like to know why this thing only puts out hot water at idle.

"Uh huh...They have apparently

"Uh huh...They have apparently honored the warranty as you have a working engine and don't appear to have an actual problem at this point. Your not understanding why or how the engine works is not covered under any warranty.

"I simply would like to know why this thing only puts out hot water at idle." It's really simple. The higher the RPM, the faster the impeller turns, the more water it pumps, the cooler that water will be.

Your next question would probably be:

Well, wouldn't higher RPM result in more heat so the water would be hotter!!!!

My answer would would be:

Yes and no. While the higher RPM would produce more heat you would have the oil circulating, and the water pump impeller spinning its little heart out. Keep in mind that the number one problem of all 4-stroke outboards is that they run cool, not hot. Run 10w-30 oil and make sure it is not synthetic.

Lastly...Relax. Your not an outboard designer or mechanic and while it may aggravate the crap out of you not to understand the "why" of it, that's not why you are out in your boat. Call it "magic" and stop worrying."