1962 Evinrude 75hp Cooling Issues?

[Bluemagoo42]

I recently acquired a 1961 Glaspar Citation that has a 1962 Evinrude Starflite 75hp motor. It has been sitting for approximately 20 years. I am somewhat familiar with boat and jet ski motors as soon as I bought the boat I installed new impeller/ water pump checked the thermostat or vernathern and had saw it was pretty corroded so I bought a new one new spark plugs fuel filter and fuel lines. Motor runs great only problem it overheats about 10 minutes after being started. I do not have a temp gauge on this boat only a red light . So I let the engine cool down and opened up the thermostat housing to see if anything was in the way.. nothing clean so I took the left and right side hoses from the tstat to heads left side was wet inside and right side seemed dry so I'm thinking there might be a blockage somewhere along the cooling passage but am clueless on where to start?

 

[jimmbo]

You need to know if water is circulating through both port and starboard sides of the engine. That engine being of an older design had a recirculating type cooling system. Myself I would be dropping the gearcase again and attach a water hose to the pipe that goes into the water pump. After I had removed the hoses between the cylinder heads and the thermostat housing I would turn on the water and see if it comes out of both heads. If not, then that head would be coming off for closer inspection of its water passages and the water jackets in the block. What condition was the old impeller?

1962 was the first year for the electric shift. Both the Electric shift and Mechanical shift versions of the 75hp were called Starflite in 62. If yours is electric, pay attention as to which oil you put in the gearcase. Best choice would be BRP Premium Blend. Type C was the spec, but unfortunately as of late there have been some brands that say Type C or Type C compatible, but then have a disclaimer not to use them in Electric shift engines. If you have the mechanical shift version, they still specified Type C, but Type C was the oil gear oil OMC marketed at the time.

 

[F_R]

Do you have it on a boat, on the lake, or do you have it in a bucket? Need I say more?

 

[Bluemagoo42]

The old impeller was still all one piece no chunks taking but still replaced with a new one and for the electric shift I'm not sure if it is or not as for the oil it's calling for 24:1 and I feel like that's a lot of oil to gas- when I get home from work I will try the hose method and yes I have it inside a 55 gallon drum.

 

[F_R]

Then make sure it is deep enough. The water pump must be well submerged before starting the motor. It is not self priming. And too much throttle, air bubbles in water or turbulence will also affect the pump. It was designed to be run on a boat on the lake.

Sure, it will run on 50:1 and it might not hurt it. You can find all the opinions you want on that subject.

If it has a gearshift handle on the side of the motor, it is not electric shift.

 

[Bluemagoo42]

Yes the gear shifter is on the right side of the motor and I am pretty sure it is getting water through the pump when I first start it there is little almost no spray then about 5 minutes into idle it has a heavy mist then shortly after I get a red light "engine overheated" and I never throttle up in the bucket due to bubbles and what not this is all at idle.

 

[F_R]

Sounds pretty normal as far as the light spray until the thermostat opens. But the hot light certainly should not be coming on. So either it is not pumping enough water or it is plugged up somewhere. Hard to tell what it is from a distance.

 

[Bluemagoo42]

And when I attach the hose to the water tube should I do it with the engine running or off

 

[jimmbo]

Actually you could leave the lower unit on, run the engine in a test tank with the hoses off. I wanted you to see if there was a blockage on the one side, as you said one of the hoses was dry. I originally said to take the lower unit off and use a water hose, but a flow check can be done by running the engine

Any knowledge of the engines history? Saltwater?

 

[Bluemagoo42]

So hook directly to the head and see if it flows out the other side? Just didn't know if it would harm if water was going through without the engine

 

[jimmbo]

So hook directly to the head and see if it flows out the other side?

That's not what I said.

 

[Bluemagoo42]

Somewhere you have confused me. If the hoses are off there will be no water pumping through the heads it would just be shooting out of the thermostat housing wouldn't it? Not familiar with the cooling system on this motor or is it always circulating and then goes to the tstat?

 

[jimmbo]

The water flows thru the exhaust cover, then thru the block and into the heads, then routed to the thermostat. There it is ether sent back to the water inlet passage to return to the water pump, or routed to the exhaust tube and idle relief. There are plenty of places to get clogged up

 

[Bluemagoo42]

Ok when I get home I will check to see what's up. I know for sure the left side is pumping water either in or out its wet but the right seemed dry so if I'm correct I should see water coming out from both sides?

 

[Bluemagoo42]

So I got back to the house and pulled the hoses off and a few moments after start up water started coming out of the left side then the right side started a stream. It seems like I got the hot engine light after 5 minutes of start up