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Kubota B6100 Troubleshooting

The Kubota B6100 sub compact tractor was manufactured from 1978 to 1997. This model was designed in 4 versions: B6100E (2WD Gear), B6100D (4WD Gear), B6100HST-E (2WD Hydrostatic), and B6100HST-D (4WD Hydrostatic). The Kubota B6100 tractor is powered by 41.2 cubic inches (675 cc) Kubota D650-A 4-cycle vertical three-cylinder liquid-cooled diesel engine.

The engine has a cylinder bore of 2.52" (64 mm), piston stroke of 2.76" (70 mm), rated power of 14.3 hp (10.6 kW), and 36.5 Nm (27.1 lb-ft) of max torque at 1800 rpm. The Kubota B6100 is fitted with two transmission options: mechanical transmission with 6 forward and 2 reverse gears, or 2-range hydrostatic transmission with infinite forward and reverse gears. The maximum travel speed (forward and reverse): 9.1 mph (14.5 km/h) / 6.2 mph (10.1 km/h).

The Kubota B6100 is equipped with a manual steering system, mechanical shoe (Gear) or internal expanding (HST) brakes, 4.00x9 (2WD) or 6.00x12 (4WD) front tires, and 7.00x16 (2WD) or 8.00x16 (4WD) rear tires. The gear models have a wheelbase of 48.9" (1240 mm) with 2WD or 49.1" (1245 mm) with 4WD. The HST models have a wheelbase of 54.7" (1380 mm) with 2WD or 55.1" (1390 mm) with 4WD.

Engine Troubleshooting
Engine won't start or hard to start
Fuel filter is dirty - Replace filter element
Closed fuel cock - Open fuel on-off cock to inject fuel
Fuel lines leaking air - Tighten clamps, change faulty pipes
Fuel injectors are clogged or faulty - Test fuel injectors and change if necessary
Fuel injection pump failure - Repair or change injection pump
Bad engine compression - Check and change damaged parts
Diesel shuts off during operation
Engine has not warmed up to the recommended temperature - Warm up the engine
Water, dirt, or air in fuel system - Drain, flush, fill, and bleed system
Irregular fuel injection - Adjust fuel injection timing
Plugged fuel filter - Change the filter element
Clogged or damaged injectors - Clean or replace fuel injectors
Engine stops after starting
Incorrectly set fuel injection pump timing - Check and correct adjustments
Fuel filter is dirty - Replace the filter element
Fuel injector nozzles are dirty or defective - Change or clean injector nozzles
Faulty fuel injection pump - Repair or install a new fuel pump
Dirty air cleaner element - Install new cleaner element or replace it
Engine stalls when idle
Low idle speed setting is incorrect - Correct low idle settings
Fuel injection pump is broken - Install a new fuel pump or repair
Fuel injector nozzles fault - Service or replace injector nozzles
Incorrect valve clearance - Adjust valve clearance
Engine overheating
Lack of coolant in cooling system - Add the coolant. Inspect the system for leaks
Cooling system components are failed or system is clogged - Flush cooling system or change faulty components
Lack of engine oil - Fill the crankcase with engine oil
Damaged fan belt or incorrect belt tension - Adjust belt tension properly or change it
Thermostat fault - Check and change if necessary
Diesel engine is losing power
Fuel injectors are defective or dirty - Change fuel injectors
Incorrect fuel injection pressure - Adjust pressure to proper level
Dirty air filter element - Replace or clean the air filter element
Dirty oil filter element - Service or change engine oil filter element
Engine is overloaded - Load reducing is recommended
Valve clearance is not correct - Adjust valve clearance according to specifications
Low idle speed adjustment is incorrect - Normalize low idle speed
Dirty fuel pipes or hoses - Service fuel pipes and hoses
Insufficient engine compression: Valves are broken or leaking - Valves need to be replaced
Engine noises or knocks
Timing of fuel injection pump is wrong - Fuel pump timing settings need to be corrected
Fuel injector nozzles are defective or dirty - Install new set of properly balanced nozzles
Engine oil level is insufficient - Fill up the engine oil
Low coolant temperature - Warm up engine as required
Main bearings or crankshaft are worn out - Replace crankshaft or bearings
Stuck or worn piston rings - Replace the piston rings as required
Flywheel mounting screws are loose - Tighten the screws
Excessive engine oil consumption
Oil leaking: Defective seals or gaskets - Change to repair leaks
Incorrect oil viscosity - Use oil of correct viscosity
Worn or stuck piston rings - Change the piston rings as required
Worn valve stems and valve guides - Replace defective valves
Pistons or cylinder liners are scored - Inspect pistons and liners, fit new components as necessary

Electrical System Troubleshooting
Battery cannot be charged
Battery is worn - Change the battery
Damaged battery wiring harness - Inspect wiring for damage, replace or repair
Battery terminals and cables are corroded or loose - Tighten or clean terminals and cables
Damaged belt or incorrectly adjusted belt tension - Change belt or adjust belt tension properly
Starter turns slowly
Low battery power - Charge the battery
Battery is draining quickly - Service charging system or replace battery
Bad battery cable harness - Inspect cables for malfunctions, repair or change
Loose or corroded cables and terminals - Service or tighten battery cables and terminals
Starter motor is not working
Low battery output - Low battery charging, charge as required
Discharged or worn battery - Charge or change the battery
Defective starter motor - Repair or install a new starter
Incorrectly connected or disconnected wires - Check battery wires and connect correctly

Transmission Troubleshooting
Hard shifts
Incorrectly adjusted or damaged clutch - Clutch needs to be replaced or adjusted
Damaged or loose gear shift linkage - Service or replace shift linkage
Shift forks are worn or damaged - Change the shift forks
Faulty parts in the gear shifting mechanism - Change faulty parts
Lack of transmission oil pressure
Fluid level is low - Check transmission fluid level and add it as required
Dirty transmission oil filter (if fitted) - Change or service the transmission oil filter
Faulty relief valve - Replace relief valve
Transmission makes excessive noise
Cracked or worn bearings - Bearings replacement required
Not enough fluid in transmission - Add transmission fluid as required
Dirty transmission oil - Transmission oil must be changed
Defective gears or incorrect backlash - Set backlash properly or change the gears
Shift forks are worn or damaged - Replace defective shift forks
Transmission oil leakage
Broken gaskets or seals - Install new components
Cracked transmission housing - Housing needs to be replaced

Hydrostatic Transmission Troubleshooting
HST transmission is excessively noisy
Dirty transmission oil or insufficient oil level - Change the oil or fill to required level
Speed control rod linkage is damaged or unadjusted - Repair or adjust link rod linkage
Relief valve is defective - Replace the valve
Transmission overload - The load should be reduced
Transmission components are worn or damaged - After disassembly and checking, replace worn components
Transmission oil overheated
Not enough oil in transmission - Check transmission oil level and add oil as required
Clogged transmission fluid filter element - Change or clean the transmission fluid filter
Cooling components are plugged or defective - Check all cooling components and change or repair if required
Excessive transmission load - Reduce transmission load
Low power
Not enough oil in transmission - Checking transmission oil level and add if necessary
Low charge pressure - Test charge pressure
Relief valve is worn or defective - Replace relief valve as required
Transmission oil leakage
Gaskets or seals are damaged - Replace worn seal or gaskets
Internal transmission case pressure is too high - Replace defective components
Clogged transmission fluid drain line - Service or replace drain line

Hydraulics Troubleshooting
Hydraulic system overheating
Hydraulic system pressure is not adjusted correctly - Correct adjustment is required
Faulty or incorrectly adjusted main relief valve - Adjust or replace the relief valve
Hydraulic oil contamination - Change the oil
Air trapped in the hydraulic system - Check the pump seals, suction line, and fittings
Hydraulic fluid pressure is insufficient
Lack of hydraulic fluid - Need to add fluid
Hydraulic fluid filter element clogging - Replace filter element or clean if required
Damaged hydraulic oil pump - Flow-rate hydraulic pump and replace pump if necessary
Defective or incorrect setting hydraulic control valve block - Adjust properly or replace
Broken hydraulic cylinder - Inspect the hydraulic cylinder components for damage or wear and change if required
Hydraulic pipes are leaking - Inspect hydraulic system for leaks and repair it
Three-point hitch lifting is too slow or cannot be lifted
Lack of hydraulic fluid - Add fluid to the hydraulic system
Hydraulic oil is too cold - Allow oil to warm
Hydraulic oil filter is dirty - Service or replace the hydraulic filter
Hydraulic pump not working - Check hydraulic pump flow and replace pump if necessary
Main relief valve malfunction or incorrect adjustment - Adjust relief valve or change if required
Hydraulic control valve is defective or set improper - Replace or adjust correctly
Broken hydraulic cylinder - Inspect cylinder parts for wear or damage and replace if required
Damaged or disconnected suction pipe - Connect or replace
Hitch does not lower or lowers very slowly
Hydraulic spool valve block is faulty or out of adjustment - Replace or adjust correctly
Defective hydraulic cylinder - Check cylinder components for wear or damage and change if necessary
Damaged lift arm shaft - Replace the shaft
The hitch is defective if there is internal mechanical damage - Change worn or damaged hitch components
Hitch raises or lowers not smoothly
Air trapped in the hydraulic system - Check the pump seals, suction pipe, and fittings
Contaminated hydraulic fluid - Change hydraulic fluid
Hydraulic pump failure - Flow-rate hydraulic pump and replace pump if necessary
Hydraulic spool valve block is defective or set improper - Change or adjust correctly
Faulty hydraulic cylinder - Inspect cylinder parts for wear or damage and replace if required

Steering System Troubleshooting
Hard Steering
Steering knuckle or steering column is stuck - Inspect steering column and knuckle, replace worn parts
Steering gearbox components are worn - Replace defective components of steering gearbox
Faulty drag link or tie rod - Replace or repair
Insufficient lubrication in steering box - Need to lubricate the gearbox
Not adjusted toe-in alignment - Check and adjust toe-in
Tires are not correctly inflated - Inflate tires as necessary
Excessive steering wheel free play
Steering column bearing or shaft is worn - Change faulty parts
Steering linkage assembly is worn or loose - Repair or replace steering linkage
Worn steering gearbox bearings - Replace the bearings
Front wheel hub bearings or steering knuckles are worn - Change hub bearings or knuckles
Damaged or worn steering tie-rod ends - Change faulty part
Tractor pulls to right or left
Worn or loose steering linkage assembly - Repair or replace steering linkage
Defective steering knuckle bushing - Replace knuckle bushing
Uneven tire pressure - Inflate the tires properly
Toe-in adjustment is incorrect - Adjust toe-in correctly



Farm Tractors Technical Specifications
JD 1026R JD 3650 JD 6400 JD 7810
FORD 1320 FORD 2810 FORD 3930 FORD 5600
MF 250 MF 690 MF 3060 MF 6180
NH TC48DA NH M100 NH T7550 NH 8560
CASE IH 495 CASE IH 1255XL CASE IH 2140 CASE IH 2294