Troubleshooting - Cub Cadet 439 Operator's Manual

6
Trouble
Shooting
For repairs beyond
the minor adjustments
listed here, contact
an authorized service
dealer.
Problem
Engine fails to start
Engine runs erratic
Engine overheats
Occasional skips
(hesitates) at high speed
Idles poorly
Excessive Vibration
Mower will not mulch grass
Uneven cut
Cause
1. Blade control disengaged.
2. Spark plug wire disconnected.
3. Fuel tank empty or stale fuel.
4. Fuel valve closed.
5. Faulty spark plug.
6. Blocked fuel line.
7. Engine flooded.
1. Spark plug wire 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. Carburetor out of adjustment.
1. Engine oil level low.
2. Air flow restricted.
3. Carburetor not adjusted properly.
1. Spark plug gap too close.
2. Carburetor idle mixture adjustment
improperly set.
1. Spark plug fouled, faulty or gap too wide.
2. Carburetor improperly adjusted.
3. Dirty air cleaner.
1. Cutting blade loose or unbalanced.
2. Bent cutting blade.
1. Wet grass.
2. Excessively high grass.
3. Dull blade.
1. Wheels not positioned correctly.
2. Dull blade.
12
Remedy
1. Engage blade control.
2. Connect wire to spark plug.
3. Fill tank with clean, fresh gasoline.
4. Open fuel valve. See engine manual.
5. Clean, adjust gap, or replace.
6. Clean fuel line.
7. Wait a few minutes to restart.
1. Connect and tighten spark plug wire.
2. Clean fuel line; fill tank with clean,
fresh gasoline.
3. Clear vent.
4. Drain fuel tank. Refill with fresh fuel.
5. Refer to engine manual.
6. Refer to engine manual.
1. Fill crankcase with proper oil.
2. Remove blower housing and clean.
3. Refer to engine manual.
1. Adjust gap to .030-inch.
2. Refer to engine manual.
1. Reset gap to .030-inch or replace
spark plug.
2. Refer to engine manual.
3. 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. Sharpen or replace blade.
1. Place all four wheels in same
height position.
2. Sharpen or replace blade.