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Mitsubishi CM4.33 Engine

The Mitsubishi CM4.33 is a 1.5 L idi (indirect) engine rated at 3000 rpm, producing up to 24.3 kW. It powers generator sets from Craftsman Marine.

Also known as: Mitsubishi CM4.33

1.5 L

Displacement

3000 rpm

Rated speed

24 kW

Gross power

On this pageSpecs Generator sets Maintenance FAQ Service intervals Torque & specs Fluids Procedures

Engine specifications

Displacement	1.5 L
Aspiration	IDI (indirect)
Rated speed	3000 rpm
Gross power	24 kW

Generator sets powered by this engine

Craftsman Marine CM4.33

How to read your Mitsubishi engine serial & model number →

Common problems

Starter motor does neither rotate nor engage
Cause: Defective or discharged battery, Burnt fuse, Loose or corroded connections in the starter circuit, Defective starter switch or relay, Defective starter motor or pinion does not engage, Starter relay not activated owing to insufficient voltage, on account of a too long cable from engine to instrument panel, Jammed components
Fix: Check battery/charge or replace and check alternator for proper functioning, Replace, Clean and tighten the connections, Replace defective component, Replace starter motor Fit an auxiliary starter relay
Oil level too low
Fix: Top up / Replace
Oil level too high
Fix: Lower oil level
Insufficient supply of combustion air
Fix: Check air inlet and ventilation openings in engine room
Incorrect SAE-specification or quality of lubrication oil
Fix: Replace by good quality engine lubricating oil
Fuel filter clogged up by water and/or dirt
Fix: Check / replace
Filter of electrical fuel lift pump clogged
Fix: Check / replace
Excessive wear and tear to cylinder or piston
Fix: Check compression; overhaul engine, if needed
Excessive inclination angle of engine
Fix: Check / adjust alignment
Engine becomes overheated
Cause: Level of cooling liquid too low, Raw water seacock closed
Defective oil filter
Fix: Check / clean or replace if necessary
Defective injector / injection pump
Fix: Check / replace
Defective electrical fuel lift pump
Fix: Replace defective component

Compiled from service & troubleshooting documentation across every generator set that uses the Mitsubishi CM4.33.

Maintenance schedule

Item	Spec	Capacity	Part #	Interval
Air filter	cooling water strainer		—
Fuel filter			—	100 hr
Oil filter			—	1000 hr
Battery			—
Belt	V-belt		—
Coolant	40% ethylene-glycol, 60% clean tap water	6.5 liters	—
Oil	15W40	6.5 litres	—	10 hr
Spark plug			—

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.

Service intervals

Item	Action	Hours	Months	Notes
Cooling liquid	Check	10 hr		Every 10 hours or daily before starting
Cooling liquid level	Check	10 hr		Every 10 hours or daily before starting
Cooling water strainer	Check	10 hr		Check for blockage of the water flow; every 10 hours or daily before starting
Engine lubricating oil	Check	10 hr		Every 10 hours or daily before starting
Engine lubricating oil level	Check	10 hr		Every 10 hours or daily before starting
Engine lubrication oil	Change	100 hr	12 mo	First service — After the first 50 hours of operation
Fuel filter	Replace	500 hr	12 mo	First service — After the first 50 hours of operation
Fuel filter/water separator	Drain	100 hr	12 mo	First service — Drain water; after the first 50 hours of operation
Gearbox lubricating fluid	Change	50 hr		First service — After the first 50 hours of operation
Idling revolutions	Adjust	50 hr		First service — Verify idling revolutions and adjust if necessary (page 15)
Idling revolutions	Check	50 hr		First service — Verify idling revolutions and adjust if necessary; after the first 50 hours
Oil filter	Replace	100 hr	12 mo	First service — After the first 50 hours of operation
Batteries, cables and connections	Check	100 hr	12 mo	After every 100 hours of operation (or at least once a year)
Gearbox lubricating fluid	Check	100 hr	12 mo	Verify level of lubricating fluid in gearbox; after every 100 hours of operation (or at least once a year)
Gearbox lubricating fluid level	Check	100 hr		After every 100 hours of operation
Impeller raw water pump	Check	100 hr	12 mo	After every 100 hours of operation (or at least once a year)
Filter before fuel lift pump	Clean	500 hr		After every 500 hours of operation (at least once a year)
Filter before the fuel lift pump	Clean	500 hr	12 mo	Clean the filter located just before the fuel lift pump; after every 500 hours of operation
Flexible engine mountings	Adjust	500 hr	12 mo	Verify correct compression and adjust if necessary; after every 500 hours of operation
Flexible engine mountings	Check	500 hr		Verify correct compression and adjust if necessary
Gearbox oil	Change	500 hr	12 mo	After every 500 hours of operation (at least once a year)
Hoses and hose connections	Check	500 hr	12 mo	Check for leaks
V-belt	Adjust	500 hr	12 mo	Verify the tension of the V-belt; after every 500 hours of operation
V-belt tension	Check	500 hr		Verify the tension of the V-belt
Valves	Adjust	500 hr	12 mo	Verify the tolerance of the valves; after every 500 hours of operation (at least once a year); have your dealer execute
Valves (tolerance/clearance)	Check	500 hr		After every 500 hours of operation (at least once a year)
Cooling liquid (inner cooling circuit)	Replace	1000 hr	24 mo	After every 1000 hours of operation (or at least once every two years)
Cooling liquid in the inner cooling circuit	Replace	1000 hr	24 mo	After every 1000 hours of operation (or at least once every two years)
Raw water pump	Test	1000 hr	24 mo	Verify the proper functioning; after every 1000 hours of operation (or at least once every two years)

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Service specifications

Type	Item	Value	Unit	Condition
Gap	V-belt deflection	12	mm	thumb and forefinger, force of about 10 kg
Gap	V-belt deflection	no more than 12	mm	using thumb and forefinger and a force of about 10 kg
Other	Difference between upper and lower dipstick oil marks	about 2	litres
Other	Max. installation angle (backwards)	15	degrees
Other	Max. lateral inclination angle (5 minutes max.)	30	degrees	5 minutes maximum
Other	Max. lateral inclination angle (continuously)	25	degrees	continuous
Pressure	Difference between upper and lower dipstick marks	about 2 liters	L
Pressure	Fuel lift pump suction height	1.5	m / 5 ft
Speed	Idling revolutions (CM4.33, CM4.42 & CM4.52)	about 840	rpm
Speed	Idling speed	840	rpm
Speed	Maximum number of revolutions	3000	rpm
Temperature	Engine lubrication oil temperature when draining	about 80	degrees Celsius	engine at operating temperature but stopped
Temperature	Pre-heating time at ambient temperature of 15 C or more	about 6	seconds	ambient temperature 15 C or more
Temperature	Pre-heating time at freezing temperature	up to 20	seconds	freezing ambient temperature
Voltage	Battery voltage (engine running)	between 12 and 14.5	Volt
Voltage	Battery voltage (engine stopped, switch on/pre-heat)	about 12	Volt
Voltage	Battery voltage, engine running	12 to 14.5	Volt	engine running
Voltage	Battery voltage, engine stopped and switch on 'on' or 'pre-heat'	about 12	Volt	engine stopped

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Recommended fluids

Fluid	Grade	Standard	Ambient	Capacity	Notes
Coolant	40% anti-freeze (ethylene-glycol) + 60% clean tap water	anti-freeze on the basis of ethylene-glycol		6.5 L	Capacity with inter cooler version 6.5 litres, with keel cooler version 7.2 liter. Protection against freezing: 45% anti-freeze/55% water to -35 C; 40%/60% to -28 C; 35 vol%/65% to -22 C.
Coolant	40% anti-freeze on the basis of ethylene-glycol and 60% clean tap water			6.5 L	With inter cooler version 6.5 litres; with keel cooler version 7.2 liter. Anti-freeze table: 40% antifreeze / 60% water up to -22 Cº; maximum 45% antifreeze / 55% water up to -28 Cº; minimum 35 vol% antifreeze / 65% water up to -35 Cº. Never fill with sea water.
Engine oil	SAE 15W/40	API CD, CE or CF4; CCMC D4 or D5	-15°C to 35°C	5.4 L	Maximum 5.4 litres without oil filter, maximum 5.6 litres with oil filter. 'Four seasons' lubricant recommended.
Fuel	Diesel fuel	CEN EN 590 or DIN/EN 590; DIN 51 601 (Febr. 1986); BS 2869 (1988) A1 and A2; ASTM D975-88 D1 and D2; NATO Code F-54 and F-75			Sulphur content less than 0.5%; maximum admissible sulphur percentage 1%. Winter type fuel suitable up to -15 C at ambient below zero, or diesel with additives suitable up to -20 C.
Fuel	diesel fuel (summer period)	CEN EN 590 or DIN/EN 590; DIN 51 601 (Febr. 1986); BS 2869 (1988) A1 and A2; ASTM D975-88 D1 and D2; NATO Code F-54 and F-75			Sulphur content less than 0,5%; maximum admissible sulphur percentage 1%. Winter period: use winter type fuel suitable up to -15 ºC, or diesel fuel with additives suitable up to -20 ºC.
Gear oil	ATF (Automatic Transmission Fluid, type A, suffix A)				ZF Hurth Type ZF10: 0,35 liter; Type ZF12: 1,1 liter. Technodrive Type TMC40: 0,20 liter; Type TMC40M: 0,20 liter; Type TMC60: 0,80 liter.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Procedures

Inspection and tensioning of the V-belt adjustment

Tools: Spanner 17, Spanner 13

Check the V-belt for wear and tear, cracks and fissures and ravels; replace if affected (engine not running).
Check tension: correct if it can be moved by no more than 12 mm using thumb and forefinger and a force of about 10 kg.
Loosen the bolts of the support and both bolts of the alternator.
Tension the belt by pushing the alternator outward.
First tighten the upper bolt of the alternator and thereafter the support and the lower bolt of the alternator.

Filling the engine lubrication oil installation

Fill the engine with 5 liters of lubrication oil for diesel engines (Type 15W40; API CD, CE or CF4; CCMC D4 or D5).
Fill through the filler cap on the rocker cover or through the filler pipe at the front of the engine; a second filler cap is at the starboard side next to the identification tag.
Check with the dipstick whether the level of lubricating oil is correct.

Filling the inner cooling circuit installation

⚠ Never fill the cooling system with sea water!

Remove the filler cap on top of the heat exchanger housing, or the cap on top of the expansion tank if fitted.
Fill the cooling system with 6.5 liters of cooling liquid.
Use a ready-to-use product or a mixture of 40% anti-freeze (ethylene-glycol) and 60% clean tap water.
Fill the system to about 1 cm below the bottom of the filler pipe.
Replace the filler cap and tighten the breather bolt.
After the first run, verify the level of the cooling liquid and top up if necessary.

Preparations for the new season installation

Open the fuel supply cock.
Charge the battery(ies) if necessary.
Connect the battery cables.
Verify that the cover of the raw water cooling strainer is tightened well.
Verify the tightness of the raw water pump cover and of all drain plugs.
Reconnect and tighten any hoses disconnected before winter storage.
Open the seacock of the raw water entry.
Check the level of the cooling liquid.
Make sure the engine has sufficient lubrication oil.
Start the engine and check for leaks in fuel system, cooling system and exhaust assembly.
Verify the proper functioning of all electronic parts, engine instruments, mechanical remote control and gearbox.
Check exhaust for coolant water.

Adding new oil maintenance

Tools: Funnel

Fill the engine with lubrication oil through one of both filling entries using a funnel.
Have the engine idling a few moments and check for leaks.
Stop the engine and check the oil level by means of the dipstick after about 5 minutes.

Bleeding of the fuel system maintenance

Turn the key in the start switch to the 'ON' position.
After about 1 minute the fuel lift pump will begin to operate and bleed the system automatically.
If so required the bleeding can also take place via the fuel filter (only for a 4-cylinder engine).

Changing of the engine lubrication oil maintenance

⚠ Oil temperature is about 80 degrees Celsius; watch out for burning the skin.

Tools: Special sump pump

Run engine to operating temperature, then stop.
Remove the dipstick and insert the hose of the special sump pump into the dipstick pipe.
Extract the oil by quickly pushing down the grip of the sump pump and pulling it slowly upwards.
Replace the oil filter after all oil has been drained.
Collect used oil and bring it to a service station per environmental directives.

Check the flexible engine mountings maintenance

Tools: Suitable tool

Use a suitable tool to make sure that the bolts on the engine bed and the nuts on the spindle are securely tightened.
Check that the rubber element shows no fissures; if it does, the engine mounting must be replaced.
Inspect all hoses of the cooling and fuel systems for loose connections, cracks and fissures; replace the hose if necessary.
Make sure that all and sundry bolts, nuts and screws are well tightened.
Make sure the damper element is still sufficiently flexible; if not, the engine must be realigned.

Check-up of coolant level maintenance

⚠ Open the filler cap on top of the heat exchanger housing only when the engine is cold.

Verify the level when the engine is cold.
Open the filler cap on the expansion tank (if fitted) or on top of the heat exchanger housing.
Make sure the coolant level is about 1 cm below the bottom of the filler pipe.
If required, top up with fresh cooling liquid.

Checking and cleaning of the cooling water strainer maintenance

⚠ If air is sucked into the system on account of a badly closing filter cover, there is a severe risk of overheating of the engine.

Close the raw water seacock and remove the cover from the filter housing.
Inspect for clogging by dirt.
Clean the filter element at least twice a year or whenever necessary.
Refit the cover making sure it shuts the unit off perfectly.

Checking of oil level in gearbox maintenance

Remove the dipstick from the gearbox housing and clean it.
Position it again into the opening but do not screw in, remove and verify the level of the lubricant.
If the level is too low, add fresh lubricant through the opening for the dipstick.

Checking of the cooling water strainer maintenance

⚠ If air is sucked into the system on account of a badly closing filter cover, there is a severe risk of overheating of the engine.

Each day, prior to starting, make sure that the cooling water strainer is not clogged by dirt.
Close the raw water seacock and remove the cover from the filter housing for inspection.
Clean the filter element at least twice a year, or whenever necessary.
When closing the strainer again, make sure that the cover shuts the unit off perfectly.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Common questions

What is the displacement of the Mitsubishi CM4.33?

The Mitsubishi CM4.33 has a displacement of 1.5 liters.

Which generators use the Mitsubishi CM4.33 engine?

The Mitsubishi CM4.33 powers 1 generator set(s), including Craftsman Marine CM4.33.

How often should you change the oil in the Mitsubishi CM4.33?

The Mitsubishi CM4.33 oil change interval is every 10 hours.

What is a common problem with the Mitsubishi CM4.33 engine?

A commonly reported issue on generators using the Mitsubishi CM4.33 is: Starter motor does neither rotate nor engage. Cause: Defective or discharged battery, Burnt fuse, Loose or corroded connections in the starter circuit, Defective starter switch or relay, Defective starter motor or pinion does not engage, Starter relay not activated owing to insufficient voltage, on account of a too long cable from engine to instrument panel, Jammed components. Fix: Check battery/charge or replace and check alternator for proper functioning, Replace, Clean and tighten the connections, Replace defective component, Replace starter motor Fit an auxiliary starter relay.