Troubleshooting Guide - MTD YARD MACHINES 070 Series Owner's Manual

TROUBLE SHOOTING GUIDE
Trouble
Possible Cause
Corrective Action
Engine fails to start
1. Blade control handle disengaged.
2. Spark plug wire disconnected.
3. Throttle control lever not in correct
starting position.
4. Fuel tank empty, or stale fuel.
5. Blocked fuel line (if so equipped).
6. Faulty sparkplug.
7. Engine flooded.
1. Engage blade control handle.
2. Connect wire to spark plug.
3. Move throttle lever to correct
starting position.
4. Fill tank with clean, fresh gasoline.
5. Clean fuel line.
6. Clean, adjust gap or replace.
7. Crank engine with throttle in FAST
position.
Engine runs erratic
1. Unit running in CHOKE or START
position.
2. Spark plug wire loose.
3. Blocked fuel line (if so equipped) or
stale fuel.
4. Vent in gas cap plugged.
5. Water or dirt in fuel system.
6. Dirty air cleaner.
7. Carburetor out of adjustment.
1. Move throttle lever to FAST
position.
2. Connect and tighten spark plug
wire.
3. Clean fuel line; fill tank with clean,
fresh gasoline.
4. Clear vent.
5. Drain fuel tank. Refill with fresh
fuel.
6. Clean air cleaner.
7. Adjust carburetor.
Engine overheats
1. Engine oil level low.
2. Airflow restricted.
3. Carburetor not adjusted properly.
1. Fill crankcase with proper oil.
2. Remove blower housing and clean.
3. Adjust carburetor.
Occasional skip
(hesitates) at high
speed
1. Spark plug gap too close.
2. Carburetor idle mixture adjustment
improperly set.
1. Adjust gap to .030"
2. Adjust carburetor.
Idles poorly
1. Spark plug fouled, faulty or gap too
wide.
2. Carburetor improperly adjusted.
3. Dirty air cleaner.
1. Reset gap to .030" or replace spark
plug.
2. Adjust carburetor.
3. Clean air cleaner.
Excessive vibration
1. Cutting blade loose or unbalanced.
2. Bent cutting blade.
1. Tighten blade and adapter.
Balance blade.
2. Replace blade.
Mower will not
discharge grass
1. Engine speed too low.
2. Wet grass.
3. Excessively high grass.
1. Set throttle between 3/4 and full
throttle.
2. Do not mow when grass is wet; wait
until later to cut.
3. Mow once at a high cutting height,
then mow again at desired height or
make a narrower cutting swath (1/2
width).
Uneven cut
1. Wheels not positioned correctly.
2. Dull blade.
1. Place all four wheels in same
height position.
2. Sharpen or replace blade.
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