1963 Johnson super seahorse 40hp cooling system

[scaryt5]

I pulled the bottom end off, submerged it in water and ran shaft with drill, the impeller is pumping lots of water, comes out at a good rate..my question is....the motor does not have a thermostat or relief vale in the housing. Could this be directing the water straight back back into the pump relief?????there isn't much water coming out of the exhaust, mostly steam

 

[Chris1956]

Re: 1963 Johnson super seahorse 40hp cooling system

That motor should have a thermostat, on the head, if I remember correctly. It also has a spitter high up on the midsection, but not a telltale. The spitter should spit 143* water, after the thermostat opens, and the motor is warm.

 

[scaryt5]

Re: 1963 Johnson super seahorse 40hp cooling system

my question is if the check valve is not in the housing the water will come back out to the pump instead of into the head??Is this correct, and why i can't get water to come out only steam??cannot find a diagram for water flow..

 

[Chris1956]

Re: 1963 Johnson super seahorse 40hp cooling system

There is no check valve that I know of. The water recirculates thru the pump until the thermostat opens, an then it is expelled. Most comes out above and behind the prop, which is underwater when running in a barrel

 

[R.Johnson]

Re: 1963 Johnson super seahorse 40hp cooling system

With the thermostat out, water should circulate directly through the block. Take the thermostat cover off, and start the engine. There should be a steady flow of water out the opening showing that the pump is working. If with the cover back in place, the engine over-heats, and spit's out steam, water is getting into the block, but not getting out.At the back of the engine is a cover over the exhaust housing. Remove this cover. At the top of the exhaust housing is a soft plug about the diameter of a quarter. If you remove this plug you will find three hole's in a diamond pattern. These hole's can become clogged with small rock's or sand. A dealer should have this plug, but if not, I believe it is the same size as used in the old early V-4 carb. on the front face.

 

[scaryt5]

Re: 1963 Johnson super seahorse 40hp cooling system

there is a valve in the bottom, under the thermostat.. i believe this is the out or relief for when the thermostat is closed... the valve was still in the block..I have a manual and it is in the diagram the head and thermostat housing..but there is no diagram for flow....I'll put it back in and see what happens, got a deeper barrel today..will try that as well...if still the same I will try what R.J. said to do, thanx