How hot should a 74 4hp johnnyrude get?

[Nos4r2]

Just done some work on my auxiliary motor (Cheers again guys).<br /> It's all together and running nicely-but there's very little water coming out of the water relief ports on the back of the leg and that comes out is cold.You can only see it by putting your hand in the path and your hand gets wet-but not hot.<br /><br />The exhaust plate gets too hot to put my hand on, but the head/block is hot enough that I can't hold my hand there for more than a couple of seconds. This is after 2-3 minutes of running.<br /><br />Is this OK? It seems a bit warm for a non-thermostatically controlled engine.

 

[tashasdaddy]

Re: How hot should a 74 4hp johnnyrude get?

sound like you have a blockage, or bad impeller, or if has the water tube is not connected correctly.

 

[Paul Moir]

Re: How hot should a 74 4hp johnnyrude get?

The exhaust plate will get burning hot since it's only incendentally cooled, and it's being blasted directly with hot exhaust out of the cylinder. Careful around it! If the head is getting that hot, it could indicate a blocked parallel coolant passage:<br /> http://www.shareaproject.com/pages/imageDetail,p,182,i,2538,00.html <br />But the head does normally get pretty hot. What you can do is feel the side of the cylinder's water jacket. on the starboard side. Not the bypass that runs down right next to it. If that's luke warm there it should be fine.<br /><br />A very good test to see if the head is overheating is to dribble a little water on it. It should wisp away, but if it sizzels at all it's too hot.<br /><br />Normally you just get a spritz out of the idle exhaust relief. But that's no indication of a blocked passage since it's probably just coming from the bypass.

 

[Xcusme]

Re: How hot should a 74 4hp johnnyrude get?

Sound like a normally running 4HP to me....