Mercury 50

TIMING, SYNCHRONIZING, & ADJUSTING
Page 2C-10 90-828631R3 MARCH 1999
Timing
WARNING
To prevent personal injury or possible death, from loss of balance or stability while
servicing the motor, DO NOT attempt to check timing while boat is in motion. Failure
to follow one of the recommended servicing procedures may result in the person
falling overboard or causing personal injury from fall in boat.
WARNING
To prevent personal injury from spinning flywheel, Do Not attempt to remove fly-
wheel cover or place hands on top of cover when checking ignition timing.
Timing Specifications
40/45
HP
Full Retarded - 5° B.T.D.C.
Full Advanced (2500-3000 rpm) - 25° B.T.D.C.
50
HP
Full Retarded - 5° B.T.D.C.
Full Advanced (2500-3000 rpm) - 35° B.T.D.C.
Ignition timing is not adjustable. The C.D.I. unit electronically controls the ignition timing.
When initially running the outboard, use a timing light to verify that the ignition timing falls
within the timing windows as described within the following tests. If the ignition timing does
not stay within the timing windows, replace the C.D.I. unit and retest. (Refer to the Ignition
Diagnostic Procedures tests in Section 2A.)
IMPORTANT: When checking the timing with the engine running, one of the following
test procedures must be followed.
Check maximum timing per specification while running the outboard:
• IN A TEST TANK
• ON A DYNAMOMETER
• ON A BOAT THAT SECURED ON A TRAILER “Backed in Water”