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John Deere E120 Troubleshooting
The
John Deere E120 lawn tractor was manufactured between 2018 and 2020. The John
Deere E120 powertrain system components: a 40.1 (656 cc) Briggs and Stratton
40N877 Intek IC 4-cycle V-twin cylinder OHV air-cooled gasoline engine with a
rated power of 20 hp (14.8 kW), and belt-driven hydrostatic transmission with
infinite forward and reverse gears.
The engine has a float-feed carburetor, integral type fuel pump, full
pressure lubrication system with spin-on oil filter, and forced air
cooling system. Max forward speed - 5.5 mph (8.8 kph), maximum reverse
speed - 3.2 mph (5.1 kph).
The lawn tractor is equipped with a manual steering system, wet disc
brakes, 15x6.00-6 front tires, and 20x8.00-8 rear tires. The wheelbase
is 49" (1240 mm). The John Deere E120 is compatible with the following
attachments: a 42" mid-mount 2-blade mower deck with cutting height of
1.0-4.0" (25-102 mm), 13 cut positions, and manual lift system, 44"
front-mount 2-stage snow blower, and 46" front blade.
Engine Troubleshooting |
Engine will not start or difficult to start |
No fuel in fuel tank - Fill gasoline up |
Incorrect fuel grade - Change gasoline |
There is air in the fuel system - Bleed the system |
Spark plug wire is disconnected or loose - Check the spark plug wire connection, repair or replace |
Spark plug is defective - Spark plug need to be replaced |
Fuel filter is clogged - Fuel filter needs changing |
Safety contact for brake pedal defective - Install new part |
Wrong carburetor adjustment - Adjusting carburetor correctly |
Low cylinder compression - Check cylinder block and replace worn parts |
Choke cable is unadjusted or damaged - Adjust correctly or change the cable |
Air intake screen is plugged - Wash or clean as required |
Ignition system malfunction - Inspect ignition system and change failed components |
Throttle cable is stuck or faulty - Clean or replace the cable |
Clogged air filter - Service or change air filter |
Dirty or faulty fuel pump - Inspect fuel pump and change as required |
Engine starts and immediately shuts off |
Spark plug is faulty - Replace spark plug |
Carburetor is dirty or faulty - Clean or change carburetor |
Ignition coil is not working - Replace ignition coil as necessary |
Broken or bad valve springs - Valve springs need to be changed |
Valves sticking - Valves need to be cleaned |
Engine oil level low - Check oil level and add oil as required |
Engine overloaded - Load reducing required |
Clogged cooling fins - Clean and wash as required |
Carburetor mixture is too lean - Adjust carburetor correctly |
Wrong ignition timing - Set the ignition timing properly |
Valve setting is incorrect - Set the valves properly |
Stale or low octane fuel - Change fuel |
Engine is overloaded - Reduce the load |
Engine oil level low - Fill the crankcase with engine oil |
Low idle speed setting is not correct - Correct idle adjustment |
Fuel pump is dirty or defective - Service or replace fuel pump |
Crankshaft or main bearings failure - Replace crankshaft or bearings |
Excessive valve clearance - Check and adjust |
Piston rings or cylinder bore are damaged - Change faulty components |
Improperly adjusted or dirty carburetor - Clean or properly adjust carburetor |
Air filter element is clogged - Replace or service air filter |
Fuel pump is dirty or defective - Service or replace fuel pump |
Defective ignition - Inspect ignition system and change failed components |
Cylinder head gasket is blown - Install new head gasket |
Valves are stuck or burned - Clean or change valves |
Push rod is worn or damaged - Push rod should be replaced |
Worn cylinder block parts - Change defective parts |
Choke did not open fully - Change or adjust choke cable |
Incorrect adjustment of carburetor main jet - Adjust the carburetor main jet properly |
Spark plug is faulty or loose - Re-tighten or replace spark plug |
Worn, stuck, or burned valves - Service or change valves |
Sleeve, piston, or rings are damaged - Replace defective components |
Incorrect valve clearance - Adjust valve clearance |
Engine consuming too much oil |
Gaskets or seals are excessively worn - Replace worn parts to avoid leaks |
Valve stems and guides are worn - Valves must be replaced |
Worn or stuck piston rings - Have piston rings replaced |
Piston or cylinder liner is scored - Check liner and piston, replace as required |
Breather pipe or hose is clogged - Replace or service |
Hydrostatic Transmission Troubleshooting |
Hydrostatic transmission makes noise |
Defective or not adjusted speed control pedal linkage - Change or adjust linkage |
Transmission overload - The load should be reduced |
Transmission oil is contaminated or oil level is insufficient - Add oil to proper level or pour fresh transmission oil |
Defective or worn transmission parts - Check transmission parts for defect or damage and change if necessary |
Rusty or worn shift linkage - Install a new gear linkage |
Seized or worn hydrostatic pump - Repair or change pump |
Misadjusted or faulty transmission shift control components - Adjust properly or change |
Transmission fluid insufficient - Add fluid to the transmission housing |
Worn or damaged drive sheave - Install a new sheave |
Shifting linkage is misadjusted or broken - Adjust properly or change linkage |
Speed control linkage is worn or unadjusted - Adjust or repair linkage |
Broken transmission gaskets or seals - Change gaskets or seals |
Final drive shaft is leaking - Shaft seals need to be changed |
Transmission case is cracked - Replace case or transmission assembly |
Mower Deck Troubleshooting |
Excessive mower vibration |
Mower deck drive pulley is worn or dirty - Clean or change pulley |
Worn or loose drive belt - Belt needs to be adjusted or replaced |
Mower blades are bent or out of balance - Change or balance blades |
Loose blade bolts tightening - Bolts should be tightened |
Discharge chute regular clogging |
Mowing speed is too high - Select a lower speed |
Grass is too long - Use a lower cutting height |
Engine runs at low revs - Choke is not fully opening |
Mower cuts too low - Change cutting height adjustment |
Drive belt installation is not correct - Install drive belt as required |
Mower deck is clogged - Need to clean the mower deck |
Blades are not sharp - Sharpen the blades |
Worn or defective blades - Blades must be changed |
High ground speed - Operate at slower speed |
Mower deck set to low cutting - Use correct cutting height |
Full bagger - Remove grass from bagger |
Blades are scalping the grass |
Lawn is uneven or bumpy - Level the lawn |
Cutting level is too low - Raise the cutting height |
Ground speed is too fast - Need to slow down |
Incorrect level of mower deck - Level the deck correctly |
Worn or bent blades - Blades need to be replaced |
Low tire pressure - Inflate tires as required |
Tires are not correctly inflated - Inflate tires as required |
Improper mower deck level - Adjust the level of mower deck correctly |
Excessive blade dullness - Blades need to be sharpened |
Worn or defective blades - Replace the blades |
Mower deck is clogged - Clean mower deck as required |
Deck shell is damaged - Replace or repair the deck |
Mower spindle is faulty or loose - Change or repair the spindle |
Electrical Troubleshooting |
Battery will not charge |
Corroded or loose cable connections - Service or tighten connections |
Battery terminal clamps are defective - Replace terminal clamps |
Battery failing - Battery change required |
Battery capacity is low - Battery is drained, charge it |
Battery won’t hold charge - Battery needs service or replacement |
Disconnected wires or corroded battery terminals - Connect wiring properly or install new terminals |
Battery is discharged or defective - Change or recharge battery |
Battery cables are disconnected or improperly connected - Inspect cables and connect properly |
Battery voltage is low - Charge the battery |
Faulty or incorrectly gapped spark plug - Replace or clean and gap |
Solenoid or starter motor is faulty - Starter/solenoid needs to be replaced |
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Lawn and Garden Tractors Technical Specs |