MTD 208cc, 179cc manual Maintaining the Engine, Spark Plug Service, Cleaning the Engine

3

Maintaining

the

Engine

WARNING

DO NOT check for spark with spark plug removed. DO NOT crank engine with spark plug removed.

If the engine has been running, the muffler will be very hot. Be careful not to touch the muffler.

Spark Plug Service

WARNING: DO NOT check for spark with spark plug removed. DO NOT crank engine with spark plug removed.

WARNING: If the engine has been run- ning, the muffler will be very hot. Be careful not to touch the muffler.

To ensure proper engine operation, the spark plug must be properly gapped and free of deposits.

1.Remove the spark plug boot and use a spark plug wrench to remove the plug, Figure 3-2.

2.Visually inspect the spark plug. Discard the spark plug if there is apparent wear, or if the insulator is cracked or chipped. Clean the spark plug with a wire brush if it is to be reused.

3.Measure the plug gap with a feeler gauge. Correct as necessary by bending side electrode, Figure 3-3. The gap should be set to 0.02-0.03 inches (0.60- 0.80 mm).

4.Check that the spark plug washer is in good condi- tion and thread the spark plug in by hand to prevent cross-threading.

5.After the spark plug is seated, tighten with a spark plug wrench to compress the washer.

NOTE: When installing a new spark plug, tighten 1/2 turn after the spark plug seats to compress the washer. When reinstalling a used spark plug, tighten 1/8-1/4 turn after the spark plug seats to compress the washer.

IMPORTANT: The spark plug must be tightened securely. An loose spark plug can become very hot and can damage the engine.

Cleaning the Engine

If the engine has been running, allow it to cool for at least half an hour before cleaning. Periodically remove dirt build-up from engine.

IMPORTANT: Do not spray engine with water to clean because water could contaminate fuel. Using a garden hose or pressure washing equipment can also force water into the muffler opening. Water that passes through the muffler can enter the cylinder, causing damage.

WARNING: Accumulation of debris around muffler could cause a fire. Inspect and clean before every use.

Spark Plug

Spark Plug Boot

Figure 3-2: The spark plug and boot.

Electrode

0.02-0.03 in.

0.60-0.80 mm

Figure 3-3: Use a feeler gauge to measure the plug gap.