Water Pumps

[Tucker]

Re: 1998 S200's. Ok, so it got above 40 deg yesterday and I bugged out of work early to get some things done. Pulled lower unit on stb motor. The area around the splne going into the powerhead was wet with premix. Bad fuel pump(s)? This motor had weak pee stream and now I now why. The dishcharge opening on the plastic pump housing was half clogged with appeared to be melted housing material. It was the same color and hard like plastic. But, I can't see any place where the plastic was melted. The metal impellar housing was fused to the plastic housing. Any ideas?

[99yam40]

What did the impeller look like?
I have seen one that was melted down to a small rubber blob due to sea weed covering the water intake.

Sounds like you need a complete water pump kit and new housing.

Not sure if premix would get to the shaft out of crankcase without the bottom seal being bad

[Tucker]

Thanks 99, I changed out the fuel pumps and fuel filter and got some fuel in the lower cowl. Think that could have gotten on the shaft? I've never heard of bottom seals going bad. Impeller looked fine. The blockage was the same color as the impeller housing; still can't figure out how it got in there. It looks as if something got into the water pump, heated up and got forced out the discharge.

[rodbolt17]

someone ran it dry.
the housing and impeller are toast.
can take less than 30 seconds dry run to toast the housing.
especially on EFI engines that start and idle high initially.
even the old bag on the water inlets typically doesnt smoke the housing, usually the engine overtemp grabs it first.