Husqvarna LC 121P Operation Manual - Page 11

MAINTENANCE LAWN MOWER Always observe safety rules when performing maintenance. TIRES • Keep tires free of gasoline, oil, or insect control chemicals which can harm rubber. • Avoid stumps, stones, deep ruts, sharp objects and other hazards that may cause tire damage. BLADE CARE For best results, mower blade must be kept sharp. Replace bent or damaged blades. • To check blade balance, drive a nail into a beam or wall. Leave about one inch of the straight nail exposed. Place center hole of blade over the head of the nail. If blade is balanced, it should remain in a horizontal position. If either end of the blade moves downward, sharpen the heavy end until the blade is balanced. BLADE ADAPTER KEY CRANKSHAFT KEYWAY BLADE CAUTION: Use only a replacement blade approved by the manufacturer of your mower. Using a blade not approved by the manufacturer of your mower is hazardous, could damage your mower and void your warranty. BLADE SCREW TRAILING EDGE CRANKSHAFT TO REMOVE BLADE (See Fig. 12) 1. Disconnect spark plug wire from spark plug and place wire where it cannot come in contact with plug. 2. Turn lawn mower on its side. Make sure air filter and carburetor are up. FIG. 12 GRASS CATCHER • The grass catcher may be hosed with water, but must be dry when used. 3. Use a wood block between blade and mower housing to prevent blade from turning when removing blade bolt. NOTE: Protect your hands with gloves and/or wrap blade with heavy cloth. 4. Remove blade screw by turning counter-clockwise. • Check your grass catcher often for damage or deterioration. Through normal use it will wear. If catcher needs replacing, replace only with approved replacement catcher shown in the Repair Parts section of this manual. Give the mower model number when ordering. 5. Remove blade. NOTE: Remove the blade adapter and check the key inside hub of blade adapter. The key must be in good condition to work properly. Replace adapter if damaged. TO REPLACE BLADE (See Fig. 12) 1. Position the blade adapter on the engine crankshaft. Be sure key in adapter and crankshaft keyway are aligned. ENGINE LUBRICATION Use only high quality detergent oil rated with API service classification SJ-SN. Select the oil's SAE viscosity grade according to your expected operating temperature. 2. Position the blade on the blade adapter aligning the two (2) holes in the blade with the raised lugs on the adapter. 3. Be sure the trailing edge of blade (opposite sharp edge) is up toward the engine. 4. Install the blade screw into blade adapter and crankshaft. 5. Use block of wood between blade and lawn mower housing and tighten the blade bolt, turning clockwise. • The recommended tightening torque is 35-40 ft. lbs. (47-54 Nm). IMPORTANT: BLADE SCREW IS HEAT TREATED. IF SCREW NEEDS REPLACING, REPLACE ONLY WITH APPROVED SCREW. TO SHARPEN BLADE NOTE: We do not recommend sharpening blade - but if you do, be sure the blade is balanced. An unbalanced blade will cause eventual damage to lawn mower or engine. NOTE: Although multi-viscosity oils (5W30, 10W30 etc.) improve starting in cold weather, these multi-viscosity oils will result in increased oil consumption when used above 32°F. Check your engine oil level more frequently to avoid possible engine damage from running low on oil. Change the oil after every 25 hours of operation or at least once a year if the lawn mower is not used for 25 hours in one year. NOTE: An oil change is not required but if you desire to change the oil follow the procedure below. • The blade can be sharpened with a file or on a grinding Check the crankcase oil level before starting the engine wheel. Do not attempt to sharpen while on the mower. and after each five (5) hours of continuous use. Tighten oil 11 plug securely each time you check the oil level.