MTD 440 Thru E459 Service And Making Adjustments, Blade Care, To Remove Blade, To Replace Blade

SECTION 8: SERVICE AND MAKING ADJUSTMENTS

Blade Care

Periodically inspect the blade adapter and pulley for cracks, especially if you strike a foreign object. Replace when necessary.

WARNING: When removing the cutting blade for sharpening or replacement, protect hands by using heavy gloves or a thick rag to grasp the cutting blade.

•Disconnect spark plug wire from spark plug.

•Turn mower on its side making sure that the air filter and the carburetor are up.

To Remove Blade

•Remove the bolt and bell washer that hold the blade-pulley assembly to the engine crankshaft. See Figure 20. Remove the assembly from the crankshaft.

•Remove the two bolts and lock nuts from the blade assembly.

•Remove the blade from the blade adapter and pulley.

To Replace Blade:

•Before reinstalling the blade-pulley assembly to the unit, lubricate the engine crankshaft and the inner surface of the blade adapter with light oil or engine oil.

•Also lubricate the bolt holes, bolt and the inner surface of the nuts.

•Install the blade adapter on the pulley with the “star” away from the pulley. See Figure 20.

Lock Nut	Pulley
	Assembly
Blade	Lock Nut
Adapter
	Blade
Hex Bolt
	Hex Bolt
Bell	Hex Bolt
Washer

Figure 20

•Place the new blade on the blade adapter with the side marked bottom (has a part number) facing away from the adapter.

•Secure the blade to the assembly with two hex bolts and lock nuts. Tighten the hex bolts to the recommended torque. Refer to ‘Blade Mounting Torque’ section below.

•Install the blade assembly on the engine crankshaft. Secure with the hex bolt and bell washer (cupped side of washer to blade) and tighten to the recommended torque. Refer to ‘Blade Mounting Torque’ section below.

IMPORTANT: The bolt used to secure the blade to the engine is specially heat-treated. Do not substitute. To order replacement bolt, refer to the parts list in the back of this manual.

WARNING: To ensure safe operation of your unit, all nuts and bolts must be checked periodically for correct tightness.

To Sharpen Blade:

•The blade can be sharpened with a file or on a grinding wheel. Do not attempt to sharpen the blade while it is still on the mower.

•Follow the original angle of grind as a guide. Make

sure that each cutting edge receives an equal amount of grinding to prevent an unbalanced blade.

An unbalanced blade will cause excessive vibration when rotating at high speeds, may cause damage to the mower and could break, and may causing personal injury. Test the blade by balancing it on a round shaft screwdriver or a blade balancer.

•If the blade is not balanced, remove metal from the heavy side until it balances evenly.

Blade Mounting Torque:

Blade adapter bolts: 120 in.lbs. minimum, 150 in.lbs. maximum.

Center bolt: 450 in.lbs. minimum, 600 in.lbs. maximum.

Battery Pack Replacement

(Electric Start Units Only)

Remove the battery pack from the handle panel for replacement only. Do not separate the batteries for any reason. Dispose of batteries properly.

WARNING: Batteries contain sulfuric acid which may cause burns. Do not short circuit or mutilate batteries in any way. Do not put batteries in fire as these may burst or release toxic materials.

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