Honda FR650 Owner's Manual page 50

Adjustment
1. Adjust by loosening the engine lock nuts and belt stopper lock nuts (2 nuts
on front side) and moving the engine back and forth.
If gap is smaller than the specified dimension: Move engine forward.
If gap is larger than the specified dimension: Move engine rearward.
BELT STOPPER (2
ENGINE LOCK NUT (4)
NOTE:
During adjustment, line up the groove of the engine-side pulley and that of the
transmission-side pulley. If they are not aligned, the belt may come off or will
wear prematurely.
ENGINE-SIDE PULLEY
TRANSilISSION-SIDE PULLEY
2.
After adjustment has been completed, fasten the nuts securely.
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