Owner`s manual

Minor Repairs
Water Pumps
There are two water pumps on the engine. The pump that is mounted into the front of the
block is the circulating pump. This pump is not rebuildable and must be replaced if a
failure occurs. The second is the raw water pump mounted to the right hand side behind
the timing gear case cover. This pump is driven by the timing gears and is a rubber
impeller type.
Servicing the pump is best done while the pump is removed from the engine although it is
not necessary if you are just replacing the impeller. To remove the pump remove the 4
nuts in the corners used to attach it to the engine. Nothing will fall out of the case so
don’t worry. Once the pump is off the engine, start by removing the screws holding the
cover to the body. This gives
access to the impeller. Remove
the impeller by taking two flat
blade screwdrivers and gently
prying up on the hub (center
section) of the impeller. It
should slide off of the shaft.
Generally an impeller
replacement is the most you
will do with the pump. If you
need to go deeper to replace
seals or bearings refer to page
68 of the service manual part
number 37600 Edition One.
Installation Hints:
Do not use any
gasket sealer on
the impeller cover
gasket. Smear the
gasket surface with
some light grease or
petroleum jelly.
When installing a
new impeller rub a
coat of light grease
on the blades.
Remove the impeller when you winterize your engine. Place a tag on the battery switch
to remind you to reinstall the impeller when you recommission in the spring.
Make sure the cover is flat and not grooved or pitted. If there is any surface imperfection
you can sand on a flat surface until smooth.
Always refer to the manual for repair specs and procedures.