Yard-Man 503 manual Maintenance

Maintenance

NOTE: When tipping the unit or emptying the fuel tank keep the air cleaner side of engine up. Never tip the mower more than 90 degrees and do not leave the mower tipped for any length of time. Oil can drain into the upper part of the engine causing a starting problem.

Engine Care

A list of key maintenance jobs, required for good performance by the mower, is given below. Follow the accompanying engine manual for details.

•Change the engine oil regularly, as instructed in the engine manual. Check oil level before starting engine every time.

•Service air cleaner every 25 hours under normal conditions. Poor engine performance and flooding usually indicate that the air cleaner should be serviced. To service the air cleaner, refer to the separate engine manual packed with your unit.

•Clean the engine periodically. Remove dirt and debris with a cloth or brush.

•Keep the cooling system (blower housing area) clean to permit proper air circulation which is essential to engine performance and life. Be certain to remove all grass, dirt, and combustible debris from muffler area.

•Clean the spark plug and reset the gap to.030” at least once a season. Refer to the engine manual for correct spark plug type.

•Inspect muffler periodically and replace if necessary.

Deck

The underside of the mower deck should be cleaned after each use to prevent a buildup of grass clippings, leaves, dirt, or other matter. If this debris is allowed to accumulate, it will invite rust and corrosion, and may prevent proper mulching, discharge, or bagging. The deck may be cleaned by tilting the mower and scraping clean with a suitable tool (make certain the spark plug wire is disconnected).

IMPORTANT: We do not recommend the use of a pressure washer or garden hose to clean your unit.

Cutting Blade Removal, Replacement, and Sharpening

WARNING: When removing the cutting blade for sharpening or replacement, protect your hands with a pair of heavy gloves or use a heavy rag to hold the blade.

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

Removing the Blade

•Disconnect spark plug wire from spark plug.

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

•Remove the bolt and the blade bell support which hold the blade and the blade adapter to the engine crankshaft. See Figure 14.

•Remove the blade and the adapter from the crankshaft.

Blade

Adapter

Blade Bell

Support

Hex Bolt

Figure 14

Sharpening the 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.

Balancing the Blade

•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 end tips facing up or 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 hex bolt 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.

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