Simplicity CFC Series Operator's Manual page 52

AdjustmBnts
ARBOR DRIVE BELT TENSION (3-Blade Mowers)
Belt tension can be increased or decreased by turning the
adjustment nut (A, figure 36) after idler pulley hardware (F) is
loosened. This nut controls the movement of the idler pulley
bracket (B) from side-to-side. Adjust belt tension so there is
3/4" deflection measured halfway between pulleys {C}.
Belt should be tight enough so there is no slippage during
operation. Over-tightening belt tension can cause premature
belt wear and pulley bearing damage. When adjustment is
correct, retighten nut on idler pulley.
Figure 36.
A. Adjustment Nut
B. Idler Pulley Bracket
C. Arbor Pulleys
D. Idler Pulley
E. Arbor Drive Pulley
F. Idler Pulley Hardware
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