Hello I am a new member

[Transamland]

Hello I just bought a 25' 1974 National pontoon with a 1979 Mercury 70 HP outboard & homemade trailer. I found some problems with the wiring. I replace the water pump and something went wrong

 

[JonBrown]

So is the problem you have the wiring or the pump?
Jon

 

[Chris1956]

Well, your wiring looks like typical 1979 Merc wiring. You should replace the engine harness. They are avail on the web.

Your waterpump looks like it has no vanes left. You should get a Merc factory service manual as the aftermarket ones are lousy.

 

[60sboater]

Sad to say,old Merc wiring often looks like that. That impeller photo looks strange...not the missing vanes but is that the remnants of the wear plate?

 

[Chris1956]

Upon further observation, the wearplate has a lot of gasket covering it. When you replace the impeller, replace the wearplate and the two gaskets. Make sure the gasket on top of the wearplate matches the waterpump cover and the one under the wearplate matches the water pump base. Lube the impeller and twist the driveshaft CW while pushing the waterpump cover over the impeller.

 

[GA_Boater]

With all the missing chunks of impeller, find as many as you can. The chunks can block passages in the block leading to hot spots or overheating.