Troubleshooting - MTD Series 400 Operator's Manual

Troubleshooting

Problem
Engine Fails to start
Engine runs erratic
Engine overheats
Occasional skips (hesitates)
at high speed
Idles poorly
Excessive Vibration
Mower will not
cut grass
Uneven cut
Mower will not self propel
Cause
1. Blade control disengaged.
2. Spark plug boot disconnected.
3. Fuel tank empty or stale fuel.
4. Engine not primed (if equipped with primer).
5. Faulty spark plug.
6. Blocked fuel line.
7. Engine ooded.
8. Fuel valve (if equipped) closed.
9. Engine not choked (if equipped with choke).
1. Spark plug boot loose.
2. Blocked fuel line or stale fuel.
3. Vent in gas cap plugged.
4. Water or dirt in fuel system.
5. Dirty air cleaner.
6. Unit running with CHOKE (if equipped)
applied.
1. Engine oil level low.
2. Air ow restricted.
1. Spark plug gap too close.
1. Spark plug fouled, faulty, or gap too wide.
2. Dirty air cleaner.
1. Cutting blade loose or badly worn.
2. Bent cutting blade.
1. Wet grass.
2. Excessively high grass.
3. Dull blade.
1. Wheels not positioned correctly.
2. Dull blade.
1. Belt not installed properly.
2. Debris clogging drive operation.
3. Damaged or worn belt.
4. Drive control out of adjustment.
Remedy
1. Engage blade control.
2. Connect wire to spark boot.
3. Fill tank with clean, fresh gasoline.
4. Prime engine as instructed in the Operation
section.
5. Clean, adjust gap, or replace.
6. Clean fuel line.
7. Wait a few minutes to restart, but do not
prime.
8. Open fuel valve. See engine manual.
9. Choke engine. See engine manual.
1. Connect and tighten spark plug boot.
Clean fuel line; ll tank with clean, fresh
2.
gasoline.
3. Clear vent.
4. Drain fuel tank. Re ll with fresh fuel.
5. Refer to engine manual.
6. Push CHOKE knob in.
1. Fill crankcase with proper oil.
2. Clean area around and on top of engine.
1. Adjust gap to .030".
1. Reset gap to .030" or replace spark plug.
2. Refer to engine manual.
1. Tighten blade and adapter. Balance blade.
2. See an authorized service dealer.
1. Do not mow when grass is wet; wait until
later to cut.
2. Mow once at a high cutting height, then
mow again at desired height or make a
narrower cutting path.
3. Replace blades.
1. Place front and rear wheels in same height
position.
2. Replace blades.
1. Check belt for proper pulley installation and
movement.
2. Stop engine, disconnect spark plug boot,
and clean out debris.
3. Inspect and replace belt.
4. Adjust drive control. Refer to page 8 in
Assembly and Set-Up.
8
15