1964 Johnson super sea horse 75 hp

[Clark hutchison]

I have what i am told is a 1964 super seahorse 75 hp outboard. It starts up but can not see it peeing it sounds good only let it run a few seconds no pee hole. I have it connected to a hose with the adapter on the foot, i have looked every where and can not even see a hole for it to pee out off. There is 2 about 3/4 inch hoses on the back that connect to what i think is the water pump. (Not sure) Can any one tell me for sure where the water pump is and where is the pee hole. Ok i am a dumb a__ this old of a motor does have a pee hole and if so can the pump go out while it is sitting in the garage? Thanks for any help you can offer

 

[Joe Reeves]

Re: 1964 Johnson super sea horse 75 hp

The two hoses on the back of the powerhead lead to the thermostat housing... NOT to a water pump. The water pump is located just on top of the lower unit, right where the lower unit bolts up to the long exhaust housing.

Run the engine in a large trash can and have the water 2 or 3 inches above the water pump assembly (about 6" over top of the first set of lower unit to exhaust housing bolts).

There is a large exhaust relief hole at the rear portion of the engine, about half way down the long exhaust housing. When the engine is running, water should shoot out of that hole like it's blasting out of the garden hose full force.

There is no water tell tale outlet hole such as what the later model engines have.

 

[Clark hutchison]

Re: 1964 Johnson super sea horse 75 hp

Thanks Joe for the help i was not sure on this old of a motor. I will run it with a can under and hope it does not need a water pump. Probably will be hard to find. Thanks again you must be a motor geek like some people are on PC.Clarkjjjj

 

[Clark hutchison]

Re: 1964 Johnson super sea horse 75 hp

Hi Joe; still could use your help i had the water pump and had to put another impeller in. It does spit a little water now but not much. I ran it in a 40 gal can for about a half hour it not get hot what do you think is going on???? Thanks again for your time and help. Clark

 

[Joe Reeves]

Re: 1964 Johnson super sea horse 75 hp

The water level must be a few inches above the water pump as the pump is not self priming.

The water pump should be sealed good.... impeller plate to lower unit, and impeller housing to plate.

All components... housing, impeller, plate must be in good condition. A housing with a bunch of pitting and/or a plate that contains scores will present a problem.

 

[F_R]

Re: 1964 Johnson super sea horse 75 hp

Hi Joe; still could use your help i had the water pump and had to put another impeller in. It does spit a little water now but not much. I ran it in a 40 gal can for about a half hour it not get hot what do you think is going on???? Thanks again for your time and help. Clark

You should stop and figure out how that thing works. So, stop and read this: That motor has a thermotat-controlled recirculating cooling system. The water pump sends water up to the powerhead through one water tube, and it circulates through the water jackets, then is presented to the thermostat. The 'stat takes its temperature, and if it is less than 140 degrees, it sends it back down the second water tube to the water pump, which recirculates it back to the powerhead. This goes on till the 'stat decides it is warm enough, then it opens and the water is discharged out the exhaust and the pump supplies more cool water from the lake and the whole process continues. Understand this: The process is going on constantly, with the 'stat opening and closing as often as needed to maintain a constant temperature.

The "tell tale" is that big blow-hole on the backside. When the 'stat is closed, only a bit of spray is discharged. (Some discharge is required to cool the exhaust housing). Now---when the motor is idleing, it may never get hot enough to open the thermostat because of that small discharge that is cooling the exhaust housing. That is perfectly normal. In gear and pushing a boat at low to moderate speed, the discharge may come and go. Hard flat-out running will heat it up enough to open the stat and keep it open till you slow down. It will never discharge water like a garden hose. It blows out at slow speeds and sort of flows out at high speeds.

Finally, I don't know what kind of hose adapter you are using. Whatever it is, you cannot test any water pump by running on a hose. The hose is supplying water under pressure to the pump, and it really doesn't have to function at all.

Get that thing on a boat on the lake and see if it does what I just described.

BTW, this is exactly how the cooling system works on your car except a radiator takes place of the lake and no water is discharged out the exhaust pipe. It is not new, unique, or unusual.