Zenith NA665, Operator'S Manual, Page: 19 / 64

16 Rev-13 Nov 23, 2020
ACCESSORY DRIVE BELTS
Engine Belt P/N # per Engine
NA665 202334 1
NA/TA690 200577 1
TA6120 202544 - Alt/WP
202545 - Fan
2
Inspection
Check the belt for visible cracks, missing chunks, and
fraying. Small cracks on the inside of the belt are OK.
Replace the belt if cracks are visible on the outside of
the belt, chunks are missing from the inside of the belt,
or the belt is frayed.
Belt Tension
Measure the belt tension midway between the alternator
and water pump pulley as specified by the arrow in the left
figure above. Use a tensioning tool such as the one shown
in the right figure above (OTC 6673LG or equivalent).
Deflection:
A second method of measuring belt tension is to apply a
force of 50N (5kg, 11lb), and measure the deflection
between the alternator and Crankshaft pulley. If the belt
tension is not as specified, adjust it.
DEFLECTION
10 ~ 20 mm (0.390 ~ 0.780 in.)
NOTE:
"New belt" refers to a belt which has been used less than
5 minutes on a running engine.
"Used belt"
refers to a belt which has been used on a
running engine for 5 minutes or more. After installing a belt,
check that it fits properly in the ribbed grooves. Check with
your hand to confirm that the belt has not slipped out of the
groove on the bottom of the pulley. After installing a new
belt, run the engine for about 5 minutes and recheck the
belt tension.
Belt Replacement
1. Release all tension from the old belt.
2. Remove the old belt.
3. Install the new belt.
4. Apply tension to the belt as specified in "Belt
Tension".
5. Recheck tension after 1 hour of operation.
6.