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John Deere X739 Problems

John Deere X739 Engine Troubleshooting

Tractor engine starting problems

No gasoline in tank - Add gasoline.
Wrong fuel grade - Use correct gasoline grade.
Stale gasoline - Drain gasoline and change with fresh.
Water or air in fuel system - Remove air or water from system.
Plug connection defective - Check wires connection.
Spark plug not working - Change as required.
Dirty fuel filter - Replace fuel filter.
Faulty safety switch - Change damaged switch.
Incorrect carburetor adjustment - Adjust carburetor idle mixture screw.
Check and adjust governor linkage. Test compression.

Gas engine is difficult to start

Spark plug failed - Test spark and change as required.
Carburetor settings incorrect - Adjusting as required.
Dirt in fuel pipes - Service required.
Throttle cable damaged - Change the cable.
Old or incorrect fuel - Fill in proper fuel.
Electrical connections are damaged - Check and replace wires if necessary.
Failing starter - Inspect the starter and change defective parts.

Rough running engine

Cooling fins are clogged - Clean and wash cooling fins.
Electrical connections damaged - Check and restore damaged connections.
Ignition adjustment lost - Check spark plug and ignition.
Choke cable sticks - Check and repair.
Air cleaner element plugged - Change air cleaner.

Engine misses under load

Spark plug failed - Inspect spark plug wire.
Carburetor is not adjusted correctly - Adjust carburetor as required.
Ignition coil air gap incorrect - Check and adjust ignition coil air gap.

JD X739 Engine overheats

Engine overloaded - Reduce loads.
Air inlet or cooling fins blocked - Clean and wash dirty components.
Engine oil low or too high - Add or drain oil.
Improper engine oil viscosity - Change engine oil.
Check connecting rod to crankshaft bearing clearance.
Idle speed problems - Adjust fast idle.

Engine does not idle

Spark plug is loose - Check spark plug gap.
Spark plug wear - Test spark and replace as required.

Engine knocks

Stale or low octane fuel - Use proper fuel.
Engine overloaded - Reduce the load.
Low oil level - Check oil level and add if necessary.
Engine is running at low revs - Adjust the required speed.
Piston rings and cylinder bore worn - Inspect and replace if required.
Check for engine overheating from plugged cooling fins.
Checking and adjusting valve clearance.
Check for carbon build-up in combustion chamber.

Engine backfires

Check spark plug and replace if necessary.
Adjust or replace throttle.
Check and adjust carburetor.
Inspect and adjust ignition coil air gap.
Check inlet and outlet valves.
Inspect and set valve clearance.
Check flywheel key.

Engine loses power

Engine overheats - Air cleaner element plugged.
High engine oil - Excess oil needs to be drained.
Fuel pump is damage - Testing fuel pump output.
Governor is damage - Checking and adjusting governor.
Check carburetor float adjustment.
Checking engine compression.

Excessive fuel consumption

Choke didn't open fully - Replace choke cable.
Incorrect carburetor adjustment - Checking and adjusting carburetor.

Emits black smoke

Air cleaner is dirty or oiled - Clean or change filter.
Choke partially engaged - Inspect and adjust throttle.
Checking and adjusting carburetor float level.

JD X739 Electrical System Troubleshooting

Starter does not function

Fuse is defective - Check and change.
Poor terminal connection - Inspect and clean contacts.
Battery not charged - Battery charging required.
Ignition switch problems - Replace the lock.
Faulty starter - Install new starter.
Electrical wires are damaged - Replace wiring.

Battery will not charge

Faulty cell in battery - Replace the battery.
Battery cables and terminals are dirty - Inspect and Clean.

Lights do not work

Light plug defective.
Replace light bulbs.
Short circuit in electrical wires.

John Deere X739 Machine Troubleshooting

The machine vibrates

Implements driven belt damaged or worn - Check and replace worn belt.
Worn traction drive belt - Fit new belt.
Drive pulley malfunction - if required.
Mower blades problem - Replace damaged blades.

Machine does not move while engine is running

The parking brake is locked - Release the park brake.
Bypass lever is on - Disengage the bypass valve lever.
Blades loose - Tighten mower blades.
Improper blade balance - Inspect the blades and balance if necessary.
Lack of oil in transmission - Add transmission oil.

John Deere X739 Mower Deck Problems

Clogged discharge chute

Lawn mower is driving too fast - Do not use high speed.
Too high grass for mowing - Adjusting cutting height.
Grass too wet - Wait until later to cut.
Engine runs at low revs - Adjust throttle to full opening.
Loss of airflow - Check engine rpm.
Low cutting height - Adjust cutting settings.
Improper belt installation - Fit belt correctly.

Lawn mower leaving uncut grass

Mower's cutting deck is clogged - Inspect and clean cutting deck.
Defective blade - Check for blade damage and replace if necessary.
Mower deck is low from ground - Deck leveling required.
Grass bag overfilled - Clean grass bag.
Speed is very high - Choose recommended speed.

Belt Slipping

Debris in pulleys - Clean or replace.
Drive belt damage - Check and replace belt.
No belt tension required - Check belt tension.

Too much mower vibration

Mower deck clogged or in sheaves - Clean mower deck and sheave from debris.
Worn pulley or belt - Replace worn parts.
Pulleys or belt misaligned - Inspect and centering.
No blade balance adjustment - Blades need balancing.

Blades scalp grass

Cutting too low - Raise cutting height.
Mower wheels not adjusted correctly - Adjust mower deck wheels.
Tires inflated insufficient - Need to inflate tires.
Faster mower blade speeds - Adjust the blade speed.
Bent blades during operation - Replace blades.

Uneven cutting results

Mower deck not level - Adjust and level the deck height.
Tire pressure uneven - Check and inflate the tires.
Incorrect rollers height - Adjust rear or front wheel height.
Gear too fast - Use slower speed.
Blades worn - Install new blade.

JOHN DEERE TRACTORS ATTACHMENTS
420	430	455	790	990
X300	X320	X330	X350	X475
X485	X500	X540	X570	X590
X700	X720	X738	X758	1023E
2025R	2210	2520	3025E	3032E
3038E	3038R	3039R	3046R	3203
3320	3520	4052R	4066R	4100
4105	4115	4200	4310	4320
4400	4410	4520	4600	4720

JD TRACTORS TROUBLESHOOTING
2640	3040	3310	3650	4100
5050D	5090R	5410	6105R	7200R
E130	L111	LA110	LT155	X300R