Bolens 979 manual Drive Belt Removal and Replacement

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speeds. It may cause damage to the mower, and could break causing personal injury.

The blade can be tested by balancing it on a round shaft screwdriver. Remove metal from the heavy side until it balances evenly. It is recommended that the blade always be removed from the adapter when testing for balance. Before reinstalling the blade and the blade adapter to the unit, lubricate the engine crankshaft and the inner surface of the blade adapter with light oil.

Be sure to install the blade with the side of the blade marked “Bottom” (or with part number) facing the ground when the mower is in the operating position.

Slide the blade adapter onto the engine crankshaft.

Place the blade on the adapter. Be certain the blade is aligned and seated on the blade adapter flanges.

Place blade bell support on blade. Make sure the notches on the blade bell support are aligned with small holes in the blade.

Replace hex bolt and tighten to torque: 450 in. lbs. min., 600 in. lbs. max.

NOTE: To ensure safe operation of your mower, the blade bolt must be checked periodically for correct torque.

Drive Belt Removal and Replacement

Disconnect the spark plug wire and ground it against the engine.

Drain the fuel tank or place a piece of plastic beneath the cap to prevent gasoline leakage.

Place shift lever in the first position and tip the mower on its side with air filter facing up.

Remove the center bolt which secures the blade to the crankshaft followed by blade bell support, blade, and blade adapter.

Move the cutting height adjustment to the highest position.

Remove the three hex screws holding the baffle to the deck and pivot baffle towards the rear of the mower. See Figure 17.

Baffle

Figure 17

Remove the hex bolt from the rear of unit holding the transmission to the mower housing.

See Figure 18.

Cutting Height

Hex Bolt

Adjustment

 

Figure 18

Tilt the transmission forward and loosen the idler pulley bolt and lock nut half a turn. See Figure 19.

Using a pair of pliers, pull back and rotate belt keeper bracket from the slot on the idler pulley.

Slide the belt out from between the belt keeper bracket and the idler pulley.

Transmission

 

Pulley

 

Belt

 

Belt Keeper

 

Bracket

 

Idler Pulley

Transmission

Bracket

 

Idler Pulley

 

Bolt and

 

Locknut

 

Figure 19

Squeeze the belt together and push it forward, while pressing the control arm inward towards the deck and remove the six speed cable from the slot. See Figure 20.

Pivot the control arm down away from the pulley and belt.

Lift off the lower pulley assembly and remove the old belt from around the crankshaft. See Figure 20.

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Contents OPERATOR’S Manual Table of Contents Important Safe Operation Practices General OperationChildren ServiceSlope Operation Page Slope Gauge Assembling Your Lawn Mower Disconnecting Spark Plug WireSetting Up Your Lawn Mower Removing Unit From CartonKnow Your Lawn Mower Stopping EngineOperating Your Lawn Mower Attaching Side Discharge Chute MulchingAttaching The Grass Bag Emptying the Grass BagDrive Clutch Control Adjustment Cutting Height AdjustmentHandle Height Adjustment Shift Lever Cable AdjustmentEngine Adjustments General Recommendations Customer ResponsibilitiesLubrication MaintenanceCutting Blade Removal, Replacement, and Sharpening EngineDrive Belt Removal and Replacement Arm Storing your Lawn MowerControl Troubleshooting Problem Cause RemedyPage Model Part Description 747-0824 Control HandleModel 25 -0807 Spacer .385 ID x .624 OD 782-0568 Page Page MANUFACTURER’S Limited Warranty for