Exmark 4500-352 manual Wheel Drive Belt Pulley Scrapers, Engine to Mower Deck Belt, Maintenance

Maintenance

2.To tighten transmission belt, loosen the 3/8 inch nyloc nut on transmission belt idler pulley. Slide bolt inward in slot and retighten nyloc nut.

3.When properly adjusted, the belt should have 1/2 inch (1.3 cm) of deflection with three pounds of pressure on the belt midway between the transmission and engine pulley.

Wheel Drive Belt Pulley Scrapers

1.Stop engine and wait for all moving parts to stop. Engage parking brake. Remove key or spark plug wire(s).

2.Be sure mud and grass scraper, on each side, is adjusted properly and centered in the pulley grooves. The pointed part of the scraper should be centered and as deep in the pulley groove as possible without rubbing at any point.

Engine to Mower Deck Belt

1.Stop engine and wait for all moving parts to stop. Engage parking brake. Remove key or spark plug wire(s).

2.Check the adjustment of the lower blade drive linkage located between the bellcrank on the engine deck and assist arm on the mower deck. Lengthen or shorten the linkage. When properly adjusted, there should be 1/16 inch to 1/8 inch (2–3 mm) of clearance between bell-crank and transmission output shaft when belt is engaged. Make sure the assist arm is against the rear assist arm stop on the deck (see Figure 13). Push the lever down to the disengaged position. The assist arm should contact the front assist arm stop on the deck. If it does not contact, readjust so that the bellcrank is closer to the transmission output shaft.

3.Belt must be tight enough to not slip during heavy loads while cutting grass. Over-tensioning will reduce belt and spindle bearing life. To adjust belt tension, loosen the 5/16 inch 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 13). Leave a minimum of 5/16 inch (.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 12). 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.

Figure 13

48 inch Deck Shown for Reference Only

1.Pulley location for Metro

2.Pulley can be moved to the front position to tighten the belt when there is no adjustment left in the turnbuckle (48 inch deck only)

3.Belt guide must be moved to the front position if the pulley is moved. (48 inch deck only)

4.Turnbuckle

5.5/16 inch (.79 cm) minimum engagement

6.5/16 inch whizlock nut

7.Rear Assist Arm Stop

8.Assist Arm

9.Front Assist Arm Stop

10.Point “A”

4.Proper belt tension will require about 10 lb (4.5 kg) side pull on belt, halfway between pulleys (see Figure 13, item 10–Point A) to deflect belt 1/2 inch (12 mm).

5.Check belt guide under the engine deck to see that it is properly set (see Belt Guide Adjustment section). Also check the blade brake adjustment (see Blade Brake Adjustment section).

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