________________________________________________________________________________________

Home / Engines / Kubota Engines / Kubota D650

Kubota D650 Troubleshooting

Engine Model: Kubota D650
Engine Type: 4-cycle vertical 3-cylinder water-cooled diesel engine
Total Displacement: 41.2 cu.in (0.68 L)
Rated Engine Power: 14.3 Hp (11.2 kW) at 3200 rpm
Fuel System: Fuel injection pump

Engine starts hard or doesn't start

Fuel filter plugging - Change filter element.
Air in fuel tank - Bleed fuel tank.
Fuel injection nozzles are faulty or clogged - Install a new kit of correctly balanced nozzles.
Fuel injection pump is faulty - Replacement or repair required.
Wrong valve timing - Set the valve timing correctly.
Fuel pipes clogging - Service or replace fuel pipes.
Injection timing is wrong - Set up as recommended.
Worn cylinder or piston rings - Change faulty components.

Engine starts but stalls immediately

Fuel filter element clogging - Replace the filter element.
Damaged fuel injection pump - Rebuild or change fuel pump.
Air filter element clogged - Carry out maintenance on air filter.
Incorrect nozzle opening pressure - Adjust as recommended.

Engine stalls after running

Fuel injection timing is not adjusted - Use the correct fuel injection pump timing adjustment.
Fuel filter plugged - Replace the filter element.
Engine not warmed up - Warm up to required temperature.
Defective or stuck injection nozzles - Repair or replace injection nozzles.

Engine stops while idle

Incorrect low idle setting - Adjust low idle speed.
The valve clearance is not adjusted - Correct valve clearance.
Damaged fuel injection pump - Rebuild or replace pump.

Diesel engine loses power

Fuel injection nozzles are damaged or dirty - Install a new kit of correctly balanced nozzles.
Fuel hoses or lines are clogged - Clean fuel hoses and lines.
Plugged air filter - Replace air filter element.
Cylinder head gasket is defective - Replace cylinder head gasket.
Injection timing is improper - Adjust injection timing as required.
Fuel injection pump failure - Rebuild or change fuel pump.
Any of moving engine components is faulty - Change or repair damaged parts.

Engine overheating

Radiator core is dirty or radiator cap is damaged - Install new cap or clean radiator.
Engine has a lack of coolant - Add coolant and check the components of cooling system.
Broken or loose fan belt - Replace as required.
Low engine oil level - Fill up the engine oil.
Cylinder-head gasket is broken - Change cylinder head gasket.
Injection timing is incorrect - Set the injection timing correctly.

Oil pressure too low

Not enough oil in the engine - Need to add oil.
Defective oil pump - Repair or change.
Oil filter element is dirty - Replace or clean engine oil filter element.
Relief valve is defective or dirty - Relief valve need to be replaced or cleaned.
Excessive oil clearance of crankshaft bearing - Inspect and replace or repair faulty parts.
Excessive crankpin bearing clearance - Inspect and change or repair worn components.

High engine oil consumption

Oil leaks: Worn gaskets or seals - Replace defective parts.
Oil viscosity is wrong - Use oil of correct viscosity.
Seized or wear piston rings - Replace piston rings.
Valve stems or guides are damaged - Valves must be replaced.
Cylinder liners or pistons are scored - Inspect pistons and liners, change as required.

Engine knocking or noise

Low coolant temperature - Normalize the temperature by warming up the engine.
Engine oil insufficient - Checking oil level and add if necessary.
Fuel injection pump timing is not adjusted - Set it up as required.
Pistons are broken or worn - Install new pistons.
Connecting rod failure or misalignment - Connecting rod needs to be aligned or changed.

Starter motor turns slow

Battery capacity is low - Low battery charging, charge as required.
Battery discharges quickly - Service or change the battery.
Disconnected cables or faulty battery terminals - Check cable connections and replace or service terminals.

Starter does not work

Battery is low or faulty - Replace or charge as required.
Battery wiring is disconnected or improperly connected - Inspect wiring and connect as required.
Low battery voltage - Recharge the battery.
Defective starter motor - Change or repair starter.

________________________________________________________________________________________

________________________________________________________________________________________

Engines Technical Specifications
BRIGGS 28S777 BRIGGS 31H777 BRIGGS 31P977 BRIGGS 31Q777
HONDA GC135 HONDA GCV160 HONDA GS190 HONDA GX340
KOHLER CH18S KOHLER CH680 KOHLER CV460S KOHLER SV735S
KUBOTA D1305 KUBOTA D1503 KUBOTA V1903 KUBOTA 2003T
MERCURY 150 MERCURY 175 XRI MARINER 135 MERCURY 200 EFI
KAWASAKI FH430V KAWASAKI FR600V KAWASAKI FX541V KAWASAKI FD611V
BMW M20B23 BMW M40B18 BMW M43B16 BMW M50B24TU
TOYOTA 3VZ-E TOYOTA 1AZ-FE TOYOTA 1G-FE TOYOTA 1JZ-GE
NISSAN HR12DE NISSAN A12 NISSAN A15 NISSAN CA18DET