Water Pump and Cooling 1969 115 Johnson

tigerone

Cadet
Joined
Jun 23, 2007
Messages
25
Just testing my water flow, impellar, and the like. I could not tell if the engine was getting cooled because it has no tell/tale. I read another thread where someone suggested that I take off the two hoses coming from the cylinder head to the thermostat housing (I think that is what it is called) and then run the engine in water and see if water is pumping through unit. I did this and got no water at all.
I assumed the pump needed replaced unless there was a blockage in the tubes somewhere. I plugged one side of Thermostat housing (where hoses from cylinder head comes in) with my finger and put a garden hose with nozzle in other to see what kind of water came out L/U. I got water out of the Mesh intakes and out of the prop exhaust area. Looked good. Is this where the water will exit on this motor?

My front dash is a shambles right now (came that way) and I don't have any warning lights to tell me if I'm overheating.

Also, while in a tub of water, I ran the engine and manually pushed water through starboard side cylinder head with garden hose and a nozzle while running. Very little water came out the port side drain and the port side was noticeably hotter on cylinder head than the starboard side (starboard side was very cool to the touch). Should this be, or is this not a very good test to see if I have any obstructions between the heads? What does this mean?

I am going to start at a new impellar and such, because it has been sitting for four years previous to my aquiring it, and going from there. But do these "tests" with my hose prove or disprove anything that cannot be solved with a new water pump?

Sorry this is so long and so many questions. Thanks for any help!
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Water Pump and Cooling 1969 115 Johnson

drop the lower unit, you need to do the impeller anyway. put a hose to the water tube, don't use a lot of water pressure that is up in the exhaust housing, then start the motor when the stats open you will get more discharge. if the engine gets above 150 degrees the stat is bad. stat is suppose to open at 140.
 

tigerone

Cadet
Joined
Jun 23, 2007
Messages
25
Re: Water Pump and Cooling 1969 115 Johnson

Thank you for your reply. How would I know if the engine is above 150 degrees? I don't have my warning light hooked up, my dash is in shambles.
Should the head be cool to the touch if water flow is good or will it be stable at about 140 or 150?
 
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