Mercury Mark10 water pump removal

[hirschlt37]

I poster this to the classifieds….my mistake…I bought what I thought was a good deal: Merc Mark10….nice shape. But it won’t pump water and got hot(not to hot). We’ve had it apart, transmission, bearing, out but can get the water pump retainer and water pump assembly to budge! Not the best design for servicing…we’ve made the tools tried several times….I need to talk or email with someone that’s actually done this. I heard it is difficult but this seems unreasonable! HELP!! Gary

[jasonh]

They make a puller tool. Stubborn ones need to be knocked out from top. Remove powerhead. I use all old ds, push it into top of wp cartridge, push off center to get ahold of bottom of wp cartridge and knock it out. Since you say you removed bearing I am assuming you removed threaded retainer cap, which you need a tool for. You may need to cleanup or replace bottom wear plate if it gets damaged.

[mercuryman]

Go to You Tube and search for >>> mercury mark 10 impeller replacement

[billw]

Doing what Jason says is also what I do. Drive it down from the top. You will destroy the upper wear plate but those can usually still be found; or if you’re extra handy, you can make a new one. It’s just a flat stainless plate. Don’t forget that, ESPECIALLY if your plate is a different thickness than the original, you’ll have to reshim the transmission.

Long live American manufacturing!

[mercuryman]

Info from Mk 10 owners guide "When running in tank or barrel , water level must be above "Dyna-Float" cover or engine may overheat"

[dave-bernard]

not only over heat but destroy the impeller.

[hirschlt37]

Thanks for all the feedback…it’s really appreciated. More questions: the service manual indicates there is a roll pin that comes in from the side and keeps the water pump assembly from rotating, the manual goes on to say the cover plate must be tilted to be removed(get by the pin). If you remove the power head and drive down on the assembly from above,,,,does the pin interfere? I think the service manual isn’t quite clear enough…for the the first time rebuilder.

Also, I’ll look into the water level of my test tank…I trust the level only need be up to the lower ‘dyna-float’ medallion?

Thanks again…

[dave-bernard]

yes it will but once you get the assy. moving get below the plate and push the pump assy. out first the pin is for alignment only.

[jeff-register]

I have seen others flatten the stainless cover & reuse

[hirschlt37]

I’m sure I ‘cooked’ the impeller…ran the motor in a test tank with water level about 3" below the ‘dyna-float’, the motor still runs good, trans is OK….I” pull the power head…then I guess I’ll try to loosen the water pump assy. Thanks again guys…

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