Water pump question 1974 70hp Johnson

[Bass Runner]

Will all the water from the pump exit through the prop on this motor or will it come out somewhere else besides the overflow holes just below the power head? Trying to determine if the water pump is pumping a full flow. Dosnt appear to be overheating and cant seem to get the warning horn to work so a little worried.

 

[DJ]

Re: Water pump question 1974 70hp Johnson

It also exits the holes just above the cavitation plate.

 

[Bass Runner]

Re: Water pump question 1974 70hp Johnson

Well took it to the lake for the first time and low a behold it got hot just at idle, I tried it before i left the house and didn't seem to get hot on muffs but did at the lake guess it's impeller time. By the way where is the thermostat on this motor?

 

[Bass Runner]

Re: Water pump question 1974 70hp Johnson

Took the lower unit off, getting to the bolt that holds the shift linkage is a real pain, isn't the stand pipe where the water tube hooks up supposed to have a rubber gasket on it? The impeller looked a little weathered but was in one piece it looks like the motor was loosing the water before it got to the powerhead, is that possible?

 

[ob]

Re: Water pump question 1974 70hp Johnson

Yes.The discharge tube should have a rubber seal or you will lose flow .Not completely sure on your year model ,but I believe the T/stat is at the top of the powerhead just above the top sparkplug.4 bolt flange cover facing aft.Hope you plan on replacing the waterpump with new since you have it down.If the impeller cup or plate shows any signs of grooving at all ,it is best to get a complete waterpump kit.

 

[rickdb1boat]

Re: Water pump question 1974 70hp Johnson

And look around for that rubber grommet somewhere in the lower unit. Unless someone else did some work on it and never put it back in... Got to be somewhere..

 

[papasage]

Re: Water pump question 1974 70hp Johnson

i have a 74 70 hp .the tstat is as explained by ob just replaced the waterpump in mine . <br /> with a hose on it you wer probabley forcing water through the cooling system so it wouldnt run hot . yes replace the waterpump . it may not be warn but it will git stiff and wilnot pump with the blades bent back . i would git the compleat kit that way you know what you got . if a dealer isent avaible napa auto parts can git it . papasage

 

[Bass Runner]

Re: Water pump question 1974 70hp Johnson

well i checked everywhere in the lower unit and in the lower leg and no gasket to be found, i am going to repace the impellor and the rest of the plate and housing is not scored, waiting on the impellor now, the one the marina gave me was the same except the key was wrong so waiting on another impellor, is there more than one gromet for the shifter? when i pulled the lu one came off one the rod and i looked and the one at the top is still there. whats the deal on that?

 

[Bass Runner]

Re: Water pump question 1974 70hp Johnson

Can you buy the gasket for the water tube seperate i don't need the rest of the kit, had to order another impeller the marina gave me the wrong one. Drats i might get the boat in the water by the time snow flys.

 

[Bass Runner]

Re: Water pump question 1974 70hp Johnson

I looked through the mega mall and I don't even see the rubber gasket for the water pump in the full kit is that thing a special order item or will it be in kit or do i need to get ahold of Johnson for the part?