1975 70 HP Johnson ....... How do I know the pump is pumping

[MokiCruiser]

I have been working on my boat project and recently paid a mechanic $450 to go through my motor ............. he did all the tests and repairs needed including changing out the impeller so it would pump water. The trouble is that on a 1975 70 HP Johnson, when it's on the muffs with the hose on, it looks about the same when it's running or not. Now I don't doubt that he did what he said, but it would sure be nice to have some sort of indicator like my smaller kicker, a 1997 Evinrude 15 HP 2 stroke. It has a pee tube coming right out of the lower section of the upper housing, and since I hadn't run it in almost three years, I noticed when I started it the other day, getting things ready for my new boat project that it wasn't "peeing", and so bought an impeller which I will be putting on today. Is there some obvious way to see what's pumping on the 75' 70 horse Johnson?

 

[Chinewalker]

Is there a telltale on your motor? I don't think the 1975 models had one built-in, but that doesn't mean one couldn't have been added. Not hard to do - you could probably find several threads regarding adding a telltale if you poke around these forums, telling you where to place it, etc.

 

[flyingscott]

In the water is easier to tell because you will see water coming out of the relief holes. Even on muffs you should have some water coming out there and it will come out of the propeller. It may also come out of the holes right above the cavitation plate.

Several videos on youtube.

 

[racerone]

Put your hand on the exhaust cover.---If it stays cool all is well.---There are many motors ruined by the false assumption that " it is peeing " so everything is good.-----Just install a new impeller every 5 years on that motor.