Exmark Metro Series Operator's Manual page 36

c) Belt must be tight enough to not slip during heavy loads while cutting grass.
Overtensioning will reduce belt and spindle bearing life. To adjust belt tension,
loosen the 5/16" whizlock nut on turnbuckle and rotate the turnbuckle; rotate
turnbuckle toward rear of mower to tighten, and toward front of mower to
loosen belt tension (See Figure 20). Leave a minimum of 5/16" (.79 cm) of the
eyebolt threads engaged on both ends of the turnbuckle.
For 48" Decks: If there is no adjustment left in the turnbuckle and the belt is
still loose, the rear idler pulley can be repositioned in the front hole (See Figure
20). The belt guide located next to the pulley must also be repositioned in the
front hole when the pulley is moved. The turnbuckle will need to be readjusted.
Check belt tension after the first hour of operation and at least twice during the
first 24 hours of operation. Adjust as necessary.
d) Proper belt tension will require about 10 lbs. side pull on belt, halfway
between pulleys (See Figure 20, Point A) to deflect belt 1/2" (12 mm).
e) Check belt guide under the engine deck to see that it is properly set. (See
Section 5.2.7). Also check the blade brake adjustment. (See Section 5.2.6)
5.2.6 Blade Brake Adjustment:
a) Stop engine and wait for all moving parts to stop. Remove key or spark plug
wire(s).
b) Disengage blades.
c) Make sure the blade brake pad rests against the sheave. Adjust the spring
mounting bolts to properly align the pad on the sheave (See Figure 21).
d) Check the distance between the spacer and the nut at the end of the blade
brake rod. The distance should be between 1/8" and 3/16" (3 – 5 mm) (See
figure 21).
e) Engage the blade control and check to make sure the blade brake pad clears
the sheave.
FIGURE 20
MOWER DECK BELT ADJUSTMENT
FIGURE 21
BLADE BRAKE ADJUSTMENT
- 31 -
48" Deck Shown
for Reference Only
(3-5 mm)