Impeller Clearance Adjustment - Mercury jet 20 Manual

IMPORTANT: Do not sharpen or alter the top side lifting angle.
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 - Leading edge

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 - Shims
Check the impeller clearance by sliding a feeler gauge through the intake grate and measure the clearance
between the impeller edge and liner. If adjustment is required, refer to Impeller Removal and Installation.
MAINTENANCE
a
b
37
b
ob01409
b - Top side lifting angle
ob01410
b - Clearance between impeller edge and liner
a