Regal 53 SC Owner's Manual page 455

PERFORMANCE DIAGNOSTICS
PROBLEM
Excessive vibration
Poor performance
Engine speed/rpm is low
POSSIBLE CAUSE
Material obstructing propeller
Bent drive propeller shaft
Bent propeller blade
Noisy drive bearing
Damaged drive casting
Trim incorrect
Unbalanced load
Engine problem
Growth on hull
Poor quality fuel
Accumulation of bilge water
Trim tab in "up" position
30
Chapter 9
POSSIBLE FIX
Reverse engines to remove material
Call authorized Regal/Volvo dealer
Repair/replace propeller
Repair drive unit
Replace damaged casting
Adjust trim
Adjust load
Call authorized Regal/Volvo dealer
Hoist vessel; clean bottom
Call authorized Regal/Volvo dealer
Check for leaks
Check trim tab functions/pump fl u-
id levels