4
(Repair Instructions Continued)
Clean-up of Pump Housing
If necessary , clean the pump casing, volute, and casing cover
using a solvent to remove debris and corrosion particles. Use
a wire brush to further remove buildup of debris if it doesn’t
soak loose.
Seal Replacement and Pump Housing Assembly
1. Apply a light bead of RTV sealant to the top edge of the
seal cavity on the casing cover.
2. Insert the stationary portion of the new mechanical seal by
carefully pushing only on the outer metal ring as you press
it into the casing cover. Use a tool with 1 1/2” ID, such as a 1
1/2” PVC pipe, 4” long, that fits over the carbon face of the
seal, but pushes only on the metal ring to insert the seal. Be
careful to avoid scratching the seal’s carbon surface.
3. Bolt casing cover on engine. Note the arrow and word UP to
indicate orientation of the casing cover. Use bolts with
washers on them. Install o-ring on casing cover; replace with
a new o-ring if necessary.
4. Lubricate the seal cavity of the impeller with WD-40, LPS,
or equivalent, and carefully press the seal’s mating ceramic
ring in place, seating it squarely on the bottom of the
cavity.
IMPORTANT: MAKE SURE BOTH OF THE SEAL’S
SURFACES ARE CLEAN AND LUBRICATED. NEVER RUN THE
SEAL SURFACES DRY.
5. Place the key into the keyway of the crankshaft making sure
it is seated properly. Lubricate the crankshaft slightly with
WD-40, LPS or equivalent and slide impeller on shaft.
Secure the impeller.
6. It is now necessary to check the clearance between the
impeller and volute. As shown in the sketch below, measure
the inside depth of the volute case (distance A). Then
measure the distance from the casing cover to the front edge
of the impeller (distance B). The difference between the
two measurements should be between 0.024 and 0.036” or
about 1/32” clearance. If the value is out of range, remove
the impeller and adjust by adding or removing brass shims
to achieve the correct amount of clearance.
7. Place a new o-ring in the groove of the volute’s inlet if
necessary. Place the volute in place with the notch pointing
up so that it mates with the casing cover at the inlet port.
It may be necessary to tip the engine on its side for this
assembly.
8. Carefully set casing over volute and bolt casing onto casing
cover and frame. It may be necessary to tip the engine on its
side for this assembly.
9. Once assembly is complete, pull on engine recoil starter with
engine switch in OFF position to verify that the impeller
rotates smoothly without catching. Connect spark plug wire.
Assembly and inspection is now complete.
Repair Instructions
