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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 |
