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Kubota L2650 Troubleshooting

The Kubota L2650 is a L50 series compact utility tractor. This model was manufactured between 1990 and 1993. The Kubota L2650 tractor is powered by Kubota D1402 vertical three-cylinder water-cooled diesel engine.

A 85.2 cubic inches (1.4 L) engine has a cylinder bore of 3.25" (85 mm), piston stroke of 3.23" (82.4 mm), and rated power of 28.5 hp (21.3 kW). The Kubota L2650 is fitted with two types of transmission. 1st type: 8x8 mechanical shuttle transmission. 2nd type: Glide shift transmission with 8 forward and 8 reverse gears. Max. travel speed (forward and reverse): 13.3 mph (21.4 kph).

The open center hydraulic system includes a gear pump with a rated fluid flow of 8.2 gpm (31 lpm). The hydraulic system pressure is 2500 psi (172 bar). The Kubota L2650 was equipped with a power steering system, wet disc brakes, 4.00-15 (2WD) or 7.00-16 (4WD) front tires, and 11.2-24 rear tires. The wheelbase is 64.6 inches (1640 mm).

Engine Troubleshooting
Engine will not start or difficult to start
Fuel filter clogging - Install new filter element
Closed fuel supply valve - Open supply valve to inject fuel
Air in fuel lines - Bleed fuel lines
Dirty or faulty injectors - Service or change fuel injectors
Fuel injection pump is defective - Repair or install a new fuel pump
Low compression - Check and change damaged parts
Engine stalls during operation
Engine is cold - Warm up the engine
Fuel-line is leaking air - Retighten clamps, replace defective pipes
Bad fuel injection - Check and adjust
Fuel filter is dirty - Replace filter element
Fuel injectors are defective or dirty - Check fuel injectors and replace if required
Diesel starts and stalls suddenly
Timing of fuel injection pump is wrong - Correct injection timing
Fuel filter plugging - Change the filter element
Fuel injector nozzles are defective or dirty - Install a new set of well-balanced nozzles
Fuel injection pump is not working correctly - Replace or repair injection pump
Air cleaner is clogged - Change or service air cleaner element
Engine stops while idling
Improperly adjusted low idle speed - Adjust the low idle speed
Fuel injection pump is broken - Replacement or repair required
Clogged or damaged injector nozzles - Check and change nozzles as required
The valve clearance is not adjusted - Adjust valve clearance
Engine overheats
Low coolant level - Coolant needs to be refilled. Check for leaks or other malfunctions
Cooling system parts are defective or system is dirty - Replace faulty parts or flush the cooling system
Low engine oil level - Fill up the oil to required level
Fan belt tension is not adjusted or belt is broken - Replace or adjust belt tension properly
Defective thermostat - Install new thermostat
Engine power is insufficient
Faulty or dirty injectors - Clean or replace fuel injectors
Incorrect fuel injection pressure - Test fuel injection pressure and adjust it correctly
Dirty air filter - Change or replace air filter element
Oil filter element clogged - Service or replace engine oil filter
Engine is under excessive load - Load reducing is recommended
Excessive valve clearance - Adjustment procedure required
Wrong adjustment of low idle speed - Test and adjust
Restricted fuel hoses or pipes - Service fuel pipes and hoses
Lack of compression: Leaking or broken valves - Replace the valves as required
Engine knocking sound or abnormal noise
Fuel injection pump timing is incorrect - Check the fuel injection pump timing setting
Fuel injector nozzles are dirty - Service or replace injector nozzles
Engine oil insufficient - Fill up the engine oil
Engine is not fully warmed up - Normalize the temperature by warming up the engine
Worn crankshaft or main bearings - Crankshaft or bearings need to be replaced
Piston rings are defective or broken - Piston rings replacement required
Loose flywheel screws - Check the flywheel screws and tighten as required
Engine oil consumption is too high
Oil leakage: Gaskets or seals may be damaged - Worn parts need to be replaced
Incorrect oil viscosity - Use correct viscosity oil
Piston rings are defective or worn - Change piston rings
Worn valve guides and valve stems - Install new valves
Cylinder liners or pistons are worn - Inspect pistons and liners, replace as required

Electrical System Troubleshooting
Battery will not charge
Battery failing - Install a new battery
Damaged battery wiring harness - Inspect wiring for damage, replace or repair
Corroded or loose cables and terminals - Clean or tighten cables and terminals
Belt wear or improper belt tension adjustment - Adjust belt tension correctly or change belt
Starter cranks slowly
Low battery output voltage - Recharge the battery
Battery drains quickly - Service charging system or install new battery
Bad battery wiring harness - Inspect wiring for malfunctions, replace or repair
Corroded or loose battery terminals and cables - Cables and terminals must be tightened or cleaned
Starter will not work
Low battery output - Battery needs to be recharged
Drained or defective battery - Recharge or change battery
Starter motor is defective - Starter needs to be changed
Wiring is improperly connected or disconnected - Need to reconnect the wiring properly

Transmission Troubleshooting
Hard shifting
Worn or misadjusted clutch - Adjust or install new clutch
Gear shift linkage is stuck or worn - Change or repair shift linkage
Bent or worn shift forks - Install new shift forks
Faulty gear shifting mechanism - Faulty parts must be changed
Lack of transmission oil pressure
Fluid level is low - Add transmission fluid as required
Clogged transmission fluid filter element (if fitted) - Change or clean the transmission fluid filter
Faulty relief valve - Replace valve as required
Transmission noise
Damaged or worn bearings - Change faulty bearings
Oil level is low - Add transmission oil as required
Dirty transmission oil - Transmission oil must be changed
Damaged gears or improper backlash - Set backlash correctly or change the gears
Worn or damaged shift forks - Change the shift forks
Transmission fluid leakage
Seals or gaskets are damaged - Install new seal or gaskets
Transmission housing is cracked - Replace housing or transmission assembly

Hydraulics Troubleshooting
Hydraulic system is too hot
Improper pressure in hydraulic system - Adjust properly
Main relief valve incorrect adjustment or failure - Replace or set up the relief valve
Hydraulic oil is contaminated - Fill up with fresh hydraulic oil
Air enters in hydraulic system - Check the pump seals, suction pipe, and fittings
Low hydraulic fluid pressure
Hydraulic fluid level is insufficient - Add fluid to the hydraulic system
Hydraulic fluid filter clogging - Service or replace the hydraulic filter
Hydraulic pump is faulty - Test the pump performance and change pump if required
Hydraulic control valve is faulty or out of adjustment - Replace or adjust properly
Defective hydraulic cylinder - Check the hydraulic cylinder parts for damage or wear and replace if necessary
Leakage in hydraulic pipes - Inspect hydraulic system for leaks and repair it
Hitch cannot be lifted or lifting is too slow
Hydraulic fluid level is low - Fill the hydraulic system with oil
Cold hydraulic fluid - Warm up the fluid
Hydraulic fluid filter is dirty - Service the hydraulic filter or change if required
Hydraulic pump not working - Check pump flow and install new pump if necessary
Faulty or incorrectly adjusted main relief valve - Replace or set up the relief valve
Hydraulic spool valve block is not set properly or defective - Change or adjust properly
Hydraulic cylinder is defective - Inspect cylinder components for damage or wear and change if required
Broken or loose suction line - Retighten or change
Hitch drops too slowly or can't drop
Hydraulic spool valve block is not set properly or defective - Replace or set correctly
Hydraulic cylinder failure - Check the hydraulic cylinder parts for damage or wear and replace if necessary
Worn hitch cross shaft - Replace the shaft
The hitch has any internal mechanical damage - Change worn or damaged hitch parts
Jerky lifting or lowering of 3-point hitch
Aeration in hydraulic system - Inspect the suction line, pump seals, and fittings
Hydraulic fluid contamination - Change hydraulic fluid
Hydraulic pump failure - Check pump flow and install new pump if necessary
Hydraulic control valve block is not set properly or defective - Adjust correctly or change
Hydraulic cylinder malfunction - Inspect the hydraulic cylinder parts for damage or wear and replace if required

Steering System Troubleshooting
Steering wheel turns hard
Steering column is broken or incorrectly fitted - Steering column needs to be refit correctly or replaced
Air trapped in the steering system - Bleed air from system
Toe-in adjustment is incorrect - Adjust toe-in correctly
Tire pressure is improper - Inflate the tires properly
Damaged hydraulic steering pump - Steering pump needs to be repaired or replaced
Worn or damaged hydrostatic steering unit - Replace or repair steering unit as required
Relief valve is stuck or worn - Flush relief valve or change if necessary
Insufficient steering fluid - Fill up the steering fluid
Steering system oil leakage - Retighten steering pipe and hose connections
Excessive play in steering
Worn steering column shaft or coupling - Change faulty component
Hydrostatic steering unit is worn or defective - Repair or replace the steering unit
Steering pump malfunction - Steering pump needs to be repaired or replaced
Steering linkage or tie-rod ends are defective - Replace failed component
Front wheels wander to right or left
Tires are deflated - Need to inflate tires
Incorrect toe-in - Check and adjust toe-in
Steering tie-rod ends or linkage are worn - Replace damaged part
Faulty or worn hydrostatic steering unit - Check and replace as required
Faulty steering cylinder - Repair or replace steering cylinder
Damaged or improperly adjusted or worn front hub bearings - Install new bearings or adjust it correctly



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MF 250 MF 690 MF 3060 MF 6180
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CASE IH 495 CASE IH 1255XL CASE IH 2140 CASE IH 2294