Troubleshooting - Yard-Man 624 Operator's Manual

SECTION 12: TROUBLESHOOTING
Trouble
Engine fails to start
Engine runs erratic
Possible Cause(s)
PTO switch engaged.
Parking brake not engaged.
Spark plug wire(s) disconnected.
Throttle control lever not in correct
starting position.
Choke not applied.
Fuel tank empty, or stale fuel.
Blocked fuel line.
Faulty spark plug.
Engine flooded.
Unit running with CHOKE applied.
Spark plug wire loose.
Blocked fuel line or stale fuel.
Vent in gas cap plugged.
Water or dirt in fuel system.
Dirty air cleaner.
Engine oil level low.
Air flow restricted.
Engine overheats
Engine hesitates at high RPM Spark plug gap too close.
Idles poorly Spark plug fouled, faulty or gap too
wide.
Dirty air cleaner.
Excessive vibration Cutting blade loose or unbalanced.
Damaged or bent cutting blade.
Mower will not mulch grass Engine speed too low.
Wet grass.
Excessively high grass.
Dull blade.
Uneven cut Deck net balanced properly.
Dull blade.
Uneven tire pressure.
Tractor will not drive (propel) Transmission bypass valves are open.
Drive belt damaged or broken.
Control cables damaged or snapped.
Tractor drifts to the left or right Control cables out of adjustment.
Uneven rear tire pressure.
Tractor moves with control Control handles out of adjustment.
handles in neutral (STOP) Control cables out of adjustment.
position. Transmissions in need of adjustment.
Corrective Action
Place PTO knob indisengaged (OFF) position.
Engage parking brake.
Connect wire(s) to spark plug.
Place throttle lever to FAST or CHOKE, if so equipped,
_osition.
Pull the choke knob or place throttle lever in CHOKE, if
so equipped, position.
Fill tank with clean, fresh (less than 30 days old) gas.
Clean fuel line or replace fuel filter, if so equipped.
Clean, adjust gap or replace plug.
Crank engine with throttle in FAST position.
Place throttle lever in FAST position or push choke knob
inward.
Connect and tighten spark plug wire.
Clean fuel line; fill tank with clean, fresh (less than 30
days old) gasoline. Replace fuel filter, if so equipped.
Clear vent or replace cap if damaged.
Drain fuel tank. Refill with clean, fresh (less than 30
days old) gasoline.
Replace air cleaner cartridge or clean pre-cleaner, if so
equipped.
Fill crankcase with proper capacity and weight of oil.
Clean grass clippings and debris from around the
engine's cooling fins and blower housing.
Remove spark plug(s) and reset the gap at .030".
Replace spark plug(s). Set plug gap at .030".
Replace air cleaner cartridge or clean pre-cleaner, if so
equipped.
Tighten blade and spindle. Balance blade.
Replace blade.
Place throttle in FAST (rabbit) position.
Do not mow when grass is wet; wait until later to cut.
Mow once at a high cutting height, then mow again at
desired height or make a narrower cutting swath.
Sharpen or replace blade.
Perform side-to-side deck adjustment.
Sharpen or replace blade.
Check tire pressure in rear tires.
Reposition transmission bypass rods.
Replace drive belt.
See an authorized MTD service dealer to have the
control cables replaced.
Perform control cable adjustment.
Refer to tire's sidewall for proper PSI and inflate or
deflate as necessary.
See an authorized MTD service dealer to have the
tractor's drive system properly adjusted.
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