Replacing Belt And/Or Adjusting Tension; Flushing The Power Package (Alpha) - Mercury 4.3 TKS series Operation & Maintenance Manual

• 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.

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.
2. Turn the adjustment stud and loosen the belt.
3. If a new serpentine drive belt is required, remove the old belt and install a new belt onto the pulleys.
4. Put a wrench on the adjustment stud 16 mm (5/8 in.) locking nut.
5. Use a 8 mm (5/16 in.) socket and tighten the adjusting stud to adjust the belt deflection.
6. Use one of the two following methods to check for correct deflection.
a. Push down with moderate thumb pressure on the longest stretch of belt. Proper deflection is 13 mm (1/2 in.).
b. Attach the Kent Moore© belt tension gauge to the belt. The gauge has different ranges for new and used belts.
b
7. While holding the adjustment stud at the correct belt tension, tighten the 16 mm (5/8 in.) locking nut.
a
8. Operate the engine for a short period of time and recheck the belt adjustment.

Flushing the Power Package (Alpha)

Your boat comes equipped with through the sterndrive water pickups. See Sterndrive Water Pickups (following) for the
flushing procedure. Consult your authorized Mercury MerCruiser dealer for further explanation.
90-8M0113857 DECEMBER 2015
eng
mc75130-1
a
a - 8 mm (5/16 in.) adjusting stud
b - 16 mm (5/8 in.) locking nut
b
6119
a - Kent Moore belt tension gauge
b - Serpentine belt
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Section 4 - Maintenance
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