Cleaning Mower; Blade Care And Replacementt - MTD 20 Operator's Manual

Cleaning Mower

• The underside of the mower deck should be cleaned after each use to prevent a buildup of grass clippings,
leaves, dirt or other matter. Follow the steps below for this job.
NOTE: We do not recommend the use of pressure washers or garden hose to clean your unit. These may cause
damage to electric components, spindles, pulleys, bearings, or the engine. The use of water will result in shortened
life and reduce serviceability.
1. Disconnect spark plug wire. Drain gasoline from the lawn mower, or place a piece of plastic under the gas cap.
2. Tip the mower so that it rests on the housing. Keep the side with the air cleaner facing up. Hold the mower firmly.
WARNING:
Never tip the mower more than 90 degrees in any directions 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.
3. Scrape and clean the underside of the deck with a suitable tool. Do not spray with water.
4. Put the mower back on its wheels on the ground. If you had put plastic under the gas cap earlier, make sure to
remove it now.

Blade Care and Replacementt

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.
Follow the steps below for blade service:
• Disconnect spark plug wire from spark plug.
• Tip mower as specified in separate engine manual. If it does not specify 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 blade and adapter from the crankshaft.
• The blade may be resharpened by removing it and
either grinding or filing the cutting edge keeping as
close to the original bevel as possible. Do not
attempt to sharpen the blade while it is still on the
mower.
• It is extremely important that each cutting edge
receives an equal amount of grinding to prevent
an unbalanced blade.
NOTE: Improper blade balance will result in excessive
vibration causing eventual damage to the engine and
mower. Be sure to carefully balance blade after
sharpening. Possible damage resulting from blade
unbalance condition is not the responsibility of the manufacturer.
NOTE: Always remove blade from the adapter for testing balance.
• The blade can be tested for balance by balancing it on a round shaft screwdriver. Remove metal from the heavy
side until it balances evenly.
• Before reassembling the blade and the blade adapter to the unit, lubricate the engine crankshaft and the inner
surface of the blade adapter with light oil.
• Install the blade adapter on the crankshaft with the "star" away from the engine. See Figure 14. Place the blade
with the side marked bottom (or with part number) facing away from the adapter. Align the blade bell support
over the blade with the tabs in the holes of the blade and insert the hex bolt.
Blade
Hex. Bolt
Figure 14
12
Crankshaft
Blade
Adapter
Blade Bell
Support