Replacing Belt And/Or Adjusting Tension; Flushing The Power Package; Tow Sports - Mercury Mercruiser Tow Sport 5.7 MPI Manual

Section 5 - Maintenance
• 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 an 8 mm (5/16 in.) socket and tighten the adjusting stud to adjust the belt deflection.
6. Using one of the two methods following, 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 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

Tow Sports

1. If flushing the engine with the boat in the water, close the seacock or remove and plug the water inlet hose.
Page 52
mc75130-1
a
a - 8 mm (5/16 in.) adjusting stud
b - 16 mm (5/8 in.) locking nut
b
6119
a - Belt tension gauge
b - Serpentine belt
14980
90-8M0076545 NOVEMBER 2012
eng