72 evi 4hp running hot?

[dkonrai]

question,
i changed the impeller on my 72 4hp. the housing and wear plate were still like brand new, the impeller was bent so i replaced the impeller.
the engine runs fine, however i noticed the head and side cover plate is really warm, almost hot. i cant really leave my hand on the head because its so hot. it is pumping water, the water coming out of the tiny exhaust holes seems to be pretty warm as well. i am barrel testing and it has been in the triple digits here. is this common on the older 3 and 4 hp? i have a 3hp too that runs pretty hot (cant leave your hand on the motor).
there is almost no hours on the motor so im stumped. should i pull the head?? i dont want to remove the head if i dont have to.
my 58 3hp was and is the same way, but will cut out after running for 20 minutes. arrrgggghhhhh. anyone?
thanks
dino

 

[hidef]

Re: 72 evi 4hp running hot?

I have a 1975 4 horse runs the same way. It pumps water good put it does get hot and the water coming out of the relief ports is also very warm. I read somewhere to run the oil at 40:1 or even 24:1 in these small outboards to help them last. Mine has very few hours on it and I am running it rich. There is no T-stat in these little motors or if there is I haven't found it. I think it is the nature of these little engines.

 

[Rick.]

Re: 72 evi 4hp running hot?

For sure there is no thermostat so no need to go looking. The common consensus is you should be able to hold your hand on the top of the head for a slow three count. You can also buy an infrared temp. tester that you simply point and shoot a beam and it tells you the temp. of the surface your pointing at. They work well. No disrespect intended but there is no reason to go any richer than 50/1 with your mix on a 72 4HP. These engines are designed to run at that mix and anything richer is of no real use but will foul plugs and carbon up much quicker. I'm pretty sure your 58 needs a richer mix though. Best of luck. Rick.

 

[dkonrai]

Re: 72 evi 4hp running hot?

thank you both soooo much for clearing that. i had a 65 evi 5 1/2 that ran great after i changed the carb. that baby was smooth and ran pretty cool.
good to know about them running a little warm.
the 58 i run at 30-1 synthetic. smokes a little but when she is running she runs pretty good. the 78 is more or less a parts motor.
dino