________________________________________________________________________________

John Deere LT166 Troubleshooting

John Deere LT166 Engine Problems

Engine won't start

Empty fuel tank - Fill gasoline up.
Wrong grade of gasoline - Change gasoline.
Stale gas - Drain fuel and add fresh.
Clogged fuel system - Remove clogging.
Faulty spark plug wire - Check wires connection.
Faulty spark plug - Check ignition spark.
Plugged fuel filter - Fuel filter needs to be replaced.
Brake pedal not pushed down - Push the brake pedal down.
Carburetor is not adjusted - Check carburetor float adjustment.
Check and adjust governor linkage. Test compression.

Engine hard starting

Spark plug failed - Inspect the spark, replace if necessary.
Carburetor incorrectly set - Set carb correctly.
Dirt in fuel lines - Clean the system carefully.
Choke cable not adjusted properly - Checking and adjusting.
Stale or improper fuel - Drain and add proper gasoline.
Electrical connection problems - Inspect and change.
Failing starter - Check starter, repair or replace.

Engine runs unevenly

Clogged cooling fins - Clean and wash cooling fins.
Loose electrical connections - Check and repair damaged connections.
Incorrect ignition settings - Check spark plug and ignition.
Throttle cable sticks - Check and replace.
Air cleaner blocked - Clean air filter.

Engine runs but misses

Spark plug failed - Test spark plug.
Carburetor malfunction - Inspect and overhaul.
Ignition coil air gap incorrect - Check and adjust ignition coil air gap.

JD LT166 Engine overheats

Excessive engine load - Reduce loads.
Air intake screen blocked - Clean clogged components.
Too much or too little oil - Check oil level. Test engine oil pressure.
Incorrect engine oil viscosity - Change oil.
Inspect crankshaft to main bearing clearance.
Too Fast idle - Adjust fast idle.

Engine doesn't idle speed

Poor spark plug contact - Adjust spark plug gap.
Faulty spark plug - Test spark and replace as required.

Engine knocking

Low octane gasoline - Use proper fuel.
Engine overloaded - Reduce loads.
Lack of engine oil - Add to required level.
Low engine speed - Adjust carburetor as needed.
piston rings or cylinder bore damaged - Replace damaged parts.
Check for engine overheating from plugged cooling fins.
Check and adjust crankshaft end play.
Check for worn crankshaft or camshaft bearings.

Engine backfires

Check spark plug for fouled.
Check and adjust the choke.
Checking and adjusting carburetor.
Checking and adjusting ignition coil air gap.
Inspect inlet and outlet valves.
Check valve clearance, adjust if required.
Checking flywheel key.

Engine loses power

Engine overheating - Check air cleaner for plugged condition.
Overfilling engine oil - Remove excess oil.
Fuel pump is damage - Repair or replace fuel pump.
Governor not work - Repair or replace governor.
Check and overhaul carburetor.
Check engine compression.

Engine gets too much gas

Choke is not fully open - Replace throttle cable.
Carburetor is not adjusted - Adjust or repair carburetor.

Exhaust with black smoke

Air cleaner is dirty or oiled - Clean or replace filter.
Choke not fully engaged - Inspecting and adjusting choke.
Inspect carburetor needle valve and seat for wear or damage.

John Deere LT166 Electrical Troubleshooting

Starter does not function

Fuse is defective - Check and change.
Battery contacts are corroded - Clean contacts.
Battery not charged - Battery charging required.
Ignition switch defective - Change switch.
Faulty starter - Replace or repair.
Wiring damage - Replace electric wires.

Battery does not charge

One or several cells defective - Install new battery.
Battery terminals and cables are dirty - Change or clean cable.

No Lights work

Light connector defective.
Replace light bulbs.
Short-circuit in cable.

JD LT166 Machine Troubleshooting

Tractor vibrates excessively

Implements driven belt damaged or worn - Check and change worn belt.
Traction drive belt worn - Fit new belt.
Dirt on driven pulley - Change if necessary.
Unbalancing or bending of blades - Replace damaged blades.

Tractor will not move with engine running

The parking brake is locked - Release the park brake.
Bypass valve pulled out - Set bypass valve to the off position.
Mower blade could be loose - Inspect and fasten securely if necessary.
Incorrect blade balance - Inspect the blades and balance if necessary.
Transmission oil is low - Add oil to the transmission.

John Deere LT166 Lawn Mower Problems

Discharge Chute Plugged

Lawn mower is driving too fast - Operate the mower at low speed.
Grass too long - Use a shorter cutting height.
Grass too wet - Wait until the grass dries.
Low engine speeds - Open choke fully.
Airflow restriction - Check engine speed.
Lack of cutting height - Adjust cutting settings.
Belt fitted improperly - install belt as required.

Streaking of uncut grass

Mower's cutting deck is clogged - Mower deck needs cleaning.
Damaged blade - Sharpen the blade or install a new one.
Mower deck low - Adjust and level the deck height.
Bagger too full - Empty bagger.
Speed is very high - Use slower speed.

Belt slips

Pulley is dirty - Clean or replace.
Belt is loose - Check and replace belt.
No belt tension required - Belt tension needs to be adjusted.

Too much mower vibration

Debris in pulleys or in mower deck - Clean mower deck and sheave from debris.
Worn pulley or belt - Replace defective parts.
Pulleys or belt misaligned - Check and adjust.
Improper blade balancing - Balance blades properly.

Blades scalp grass

Cutting too low - Raise cutting height.
Mower height wheels not adjusted - Adjust mower deck wheels.
Insufficient tire pressure - Need to inflate tires.
Faster mower blade speeds - Adjust the speed of blades.
Bent mower blades - Install new blades.

Uneven Cut

Deck level is too low - Adjust and level the deck height.
Tire pressure unequal - Inflate tires as required.
Rollers not positioned properly - Adjust wheel heights correctly.
Ground speed too fast - Operate the mower at low speed.
Mower blades blunt - Check and replace the 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