1975 25hp Evinrude impeller install.

[calvinyonce]

I recently removed the lower unit on my 25hp 1975 Evinrude (25502B) and installed new seals in the gearcase and a new water pump housing and impeller. I tried to start the motor but it would not turn over at first. I then realized by taking the motor cover off that there was a crack in the fuel pump cap. I was able to get the motor started at one point and it ran for less than a minute. It was not pumping any water out of the exhaust port. I had the motor in a bucket but the water by pass plate was above the water line. On the second attempt at running this motor I added more water to cover the water by pass plate. The motor was shooting water out of the exhaust port as soon as I cranked it. My question is have I damaged the newly installed impeller by running the motor in to shallow of water, the water intake was under the water line so I thought I was in the clear. Also what is the by pass cover for and why is it there if the water intake is below it? Also should the lower unit be sealed with something at the seam of attachment to the exhaust housing? I was able to run the motor for several minutes but it sputters and dies and I think it is because of the cracked fuel pump cap. I have ordered a replacement for the fuel pump and hopefully this is all that is wrong. Thanks for looking!

 

[Beek14]

Re: 1975 25hp Evinrude impeller install.

Running for less than a minute, I doubt you did any damage to the water pump, however it is possible. If you can start it up and it works fine, I wouldn't worry about it. Lower unit does not need to be sealed with anything when bolted up. If fact, there should be a drain hole towards the upper part of the lower unit that allows any water that enters to drain out when out of the water.

 

[calvinyonce]

Re: 1975 25hp Evinrude impeller install.

Thanks for the info Beek14.