Serpentine Drive Belt; Checking; Replacing Belt And/Or Adjusting Tension - MerCruiser Sterndrive 4.3 MPI User Manual

Serpentine Drive Belt

Avoid possible serious injury. Make sure that the engine is turned off and the ignition key
is removed before inspecting belts.
d
a
With a seawater pump

Checking

1. Inspect the drive belt for proper tension and for the following:
•
•
NOTE: Minor, transverse cracks (across the belt width) may be acceptable. Longitudinal
cracks (in the direction of belt length) that join transverse cracks are NOT acceptable.
•
•
•

Replacing Belt and/or Adjusting Tension

IMPORTANT: If a belt is to be reused, it should be installed in the same direction of rotation
as before.
NOTE: Belt deflection is to be measured on the belt at the location that has the longest
distance between two pulleys.
1. Loosen the 16 mm (5/8 in.) locking nut on the adjustment stud.
90-864195061 NOVEMBER 2006
a
b
f
c
e
6116
a - Idler pulley
b - Water circulating pump pulley
c - Crankshaft pulley
Excessive wear
Cracks
Fraying
Glazed surfaces
Proper tension ‑ 13 mm (1/2 in.) deflection, with moderate thumb pressure, on the
belt at the location that has the longest distance between two pulleys.
WARNING
!
d
b
Without a seawater pump
d - Alternator pulley
e - Seawater pump pulley
f - Power steering pump pulley
mc75130-1
Section 5 - Maintenance
a
f
6117
c
Page 97