Installation manual

90-898305
4-12
PULSE FUEL PUMP RUNING CHANGE
There is continued improvement planned for the square pulse driven fuel
pump used on most of the larger 2 stroke outboards.
CHECK VALVE CONTACT SURFACE: The outer edge of the check valve
will contact a raised surface that improves sealing of the valve.
RAISED CENTER PORTION: The center portion of the check valve surface
in the pump housing has been raised. This will allow more clearance for debris
to pass through the check valve and pump.
RETAINER HOLE CHAMFER TOP SIDE: Currently the retainer head side of
the retainer hole has a slight chamfer. This sometimes causes the retainer
head to pull the check valve into this chamfer causing the outside edge of the
check valve to raise up which prevents good sealing of the valve.
RETAINER HOLE CHAMFER BOTTOM SIDE: The bottom side of the
retainer hole will have a chamfer added, this allows the split end of the
retainer to spread out without pulling down with excessive force. When there
is too much down pressure on the head of the rivet, the outside edges of the
check valve is raised up preventing good sealing.
RETAINER O-RING: An O-ring will be added under the retainer head, to
prevent leakage past the retainer.
a b
Notes
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