1973 Johnson 65 hp possible issue

My father in law has a mint 65 hp Johnson on his boat and he is a occasional use boater I helped him pull the boat which seems to be running fine but I noticed at the dock that at idle the two finger size ports on the rear of the motor below the hood line were dry (no water coming out)as I recall I use to see water dribbling out of them.I told him he should have that checked but he said if it aint broke,well you know the rest who is right it would be ashame to ruin this motor as I said it is mint and coming to me in the near future.

Re: 1973 Johnson 65 hp possible issue

Sounds like it may need an impeller. You should see some water spray coming out with the ehaust.

Re: 1973 Johnson 65 hp possible issue

Yes this is what I thought,he then ran the motor with muffs on it up at the cottage and indeed there was water coming out thru the prop exhaust,but still nothing at the two ports three quarters of the way up the prop shaft housing.

Re: 1973 Johnson 65 hp possible issue

Normally water will come out those ports when the mtr is in the water and warmed up and the theromostat opens. May not be a bad idea to service the water pump to be sure.

Re: 1973 Johnson 65 hp possible issue

Don't worry about it, those holes are relief ports. The main exit point for cooling water is at the gearcase. Look for a set of vertical slits on either side of the gearcase, above the cavitation plate.

When you run the motor on muffs, you are especially unlikely to see much coming out of the upper holes, because there is no backpressure against the exhaust or lower exit point for the cooling water.

The next time you start the motor up on the muffs, watch the slits that I mentioned. You shouldn't see water coming out for about ten seconds or so, then you will. That is the t-stat opening up.

If you are not seeing water flow out of the lower exit point, then you may have a problem. Regardless, if you don't know when the water pump impeller was last changed, I recommend doing so.



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Re: 1973 Johnson 65 hp possible issue

Thanks tons guys that info is so helpful,in the spring I myself will be taking it in to change out the water pump,this motor has been a rock and I want too keep it that way.