Sealant required under water pump plate? 86 Johnson 9.9

[jrs_diesel]

I am having cooling issues with my 86 9.9 HP Johnson. Yesterday I pulled the lower unit and rigged up a garden hose to supply the powerhead with water via the copper water tube. Engine didn't get hot this way, and the tell tale had a nice solid stream. So now I am looking at the water pump.

I replaced it earlier this year. The key is still on the shaft and driving the impeller. The only thing I can think of is that the grommet got folded over when I put the lower unit back on, or the pump is sucking air when the boat is on plane (overheating and intermittant tell tale stream).

I want to make sure I get this right before I take the boat out again. Do I need to put sealant under the stainless steel water pump plate? If so what kind of sealant?

 

[duke33]

Re: Sealant required under water pump plate? 86 Johnson 9.9

I don't think so, but you better wait for the more experienced to get the correct answer.

 

[jrs_diesel]

Re: Sealant required under water pump plate? 86 Johnson 9.9

Thanks for the reply Duke. I know the service manual for my 72 6 HP calls for Adhesive M under the water pump plate on the mating surface. I was think that the same was required for the 9.9, but haven't seen anything that confirms it.

 

[boobie]

Re: Sealant required under water pump plate? 86 Johnson 9.9

If it's metal to metal under the plate use 3M-847. That replaces Adhesive M. If there's no gasket between the impeller hsg and the plate use the 847 there also.

 

[raczekp1]

Re: Sealant required under water pump plate? 86 Johnson 9.9

on the top of water pump is seal.replace this seal or instal automotiv one.
also clean small hole in water pump, helping to create sucking preasure

 

[jrs_diesel]

Re: Sealant required under water pump plate? 86 Johnson 9.9

Thanks for the advice guys. I will get that sealant and seal up the water pump.

Thanks again