Looking for a schematic of the cooling system for a 1967 40hp Johnson Sea Horse

Does anyone have a detailed schematic of the cooling system for older Johnson 40hp outboards? I'm trying to determine where a blockage might be and I would like to take as little apart as possible. Most importantly where the water goes after leaving the water pump. The schematic does not have to be for my motor any one will give me an idea where to start I'm sure, any older Johnson water circuit will work. My motor is a 1967 40hp Johnson Sea Horse model# RDSL-29E.

Thanks to anyone that will help me fix this engine!

Rob

Re: Looking for a schematic of the cooling system for a 1967 40hp Johnson Sea Horse

Rarely (EXTREMELY RARE) there are internal clogs to the cooling system.

First thing to inspect is the impeller I don't care if it is a week old .....you need to remove the lower unit and check it. I have seen new ones self destruct.

Here is the path (in writing) into the inlets below the lowest plate of the motor, into the water pump, pumped up the tube to the engine block around te heads in the water jacket (passing the thermostat) and then back down to the water exit on the leg.

Here is the best answer on where to start -

Get a manual and then drop the lower unit.

Re: Looking for a schematic of the cooling system for a 1967 40hp Johnson Sea Horse

I have the manual and I have taken off the lower end four times now. The impeller that I replaced was in good condition but I replaced it anyway. I checked the housing and it seems fine, the base plate had some minor wear but still in good condition. I replaced all of the grommets and sealed the pump and tubes with silicone. Everything went together quite easily. When I turned on the engine with the thermostat out and housing cap off I still didn't get any water to the thermostat. I can't figure out why. All of the water seem to come out the lower end drain holes and not where it should. Any suggestions?