Mercury 40 Jet - Impeller Clearance Adjustment

MAINTENANCE
77
Check the impeller blades occasionally for damage. Use a flat file
to resharpen the leading edges. Sharpen to a 0.8 mm (1/32 in.)
radius by removing material from bottom side only.
a
b
29079
a - Leading edge b - Top side lifting angle
Impeller Clearance Adjustment
The impeller should be adjusted so there is approximately 0.8 mm
(0.03 in.) clearance between the impeller edge and liner. Operating
the jet drive in waters that contain sand and gravel can cause wear
to the impeller blades, and the clearance will start to exceed
0.8 mm (0.03 in.).
As the blades wear, shims located in the stack outside of the
impeller can be transferred behind the impeller. This will move the
impeller further down into the tapered liner to reduce the clearance.
a
b
29080
a - Shims
b - Clearance between impeller edge and liner