Mercury MerCruiser 4.3 TKS, User Manual

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Section 5 - Maintenance
Page 72 90-899883179 OCTOBER 2007
Serpentine Drive Belt
!
WARNING
Inspecting the belts with the engine running may cause serious injury or death. Turn off
the engine and remove the ignition key before adjusting tension or inspecting belts.
6116
a
b
c
d
e
f
a
6117
f
a
b
c
d
With a seawater pump Without a seawater pump
a - Idler pulley
b - Water circulating pump pulley
c - Crankshaft pulley
d - Alternator pulley
e - Seawater pump pulley
f - Power steering pump pulley
Checking
1. Inspect the drive belt for proper tension and for the following:
• Excessive wear
• Cracks
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.
• 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.
mc75130-1
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.