Repaired the water pump on my 470

[UNRULEE]

..............and also replaced the thermostat on my '87 470. Put the ear muffs on for a test run and the boat now wants to overheat. NEVER had an overheating issue before. Pulled the plug on the heat exchanger for the "outside" (can't think of a better term) water, and there is zero water at the drain. Why insn't my boat taking in water for cooling now???

FYI I had a new water pump put in last month with a new lower unit (long story), and have had the boat out for two weekends prior to this without any trouble. I fixed the leaking engine w/p over the weekend and now I have a heating issue.

 

[Bifflefan]

Re: Repaired the water pump on my 470

Pull off the water hose at the from of the heat exchanger, turn on the water with the muffs and run the engine for a minute see if the water comes out the hose. If yes then put it back on and go to the rear hose and remove it and see if water comes out. If yes there is an issuse with the manifold/riser.
If no water at the fisrt point then follow back and remove the hose ends one at a time till you find water and replace what is plugged up.

Is the therm in right side up?

 

[Bt Doctur]

Re: Repaired the water pump on my 470

No water there would make the riser hot too.Could be a bad impeller. I`ve had a few this year where the inner brass section came un-bonded from the rubber

 

[UNRULEE]

Re: Repaired the water pump on my 470

There was no water at either the inlet or outlet. I pulled the water intake grate off of the lower unit and found a few rubber chunks in there. I suppose the lower impeller is mostly rubber and has come apart.

We'll see if I can get a warranty repair out of the deal, the pump is less than a month old!!!