Re: Merc KE-4 7.5HP disassembly advice needed please.

[green-thumbs]

Removal of swivel pin: tap the hollow pin to create a threaded section (7’16" x 20 fine thread usually works. You may need to drill to correct tapping size. Then a section of all 7/16 x 20
threaded rod, nut, washer and a length of pipe, if it proves difficult apply heat and tighten
up nut…either swivel pin comes out or you pull the threads. Works for me.

Removing the water pump cover: it is a LEFT HAND thread so it comes off the opposite way
There are several ways to soften up a tight cover…HEAT, BEAT and your favorite solvent
to seep into threads. The Mercury Service Tool can be made (sort of) but, the real problem
is corrosion between threads of cover and case. Use grease on threads when installing
cover.
Water pump housing has two threads so it can be (in theory anyway) be pulled out using
screws, nuts and a plate drilled to fit over prop shaft with holes for the two screws that
engage water pump cartridge. Usually the threads in water pump cartridge have been messed up so on to plan B. Pad prop shaft in vise and use soft mallet to drive gear case
assembly away from water pump cartridge…this will bring out several parts that have
to be reinstalled in same order…ALSO water pump cartridge has to be installed so inlet
and outlet are lined up or "clocked" Mark cartridge and case with magic marker or similar
to make this obvious when installing. Seal is installed in grease chamber side of water
pump cartridge and this is the way to get at it. Heating case may assist in removal and
installing. Cartridge is a friction fit in gear case. Take photos to aid in remembering which
parts go where. If you work carefully this should be a mild learning experience. It is vital that
you pay close attention when taking it apart so you avoid problems putting it back together.

When you get it back together and it meshes and turns smoothly give yourself a pat on the back. It is not unknown for gears to be damaged or corroded, bearings to be rusted and
shafts to be be worn, grooved or rust pitted. It may be more cost effective to seek a good
used gear case water pump assemby than to track down gears, shafts and bearings.
Seals them selves are nominal cost but shaft has to be smooth. round and concentric to
seal lips…If you can make tools approximating the Mercury Service Tool life is easier.

Louis