Yanmar 3TNE78A-ADCL Engine

⚠ Adjust valves after cylinder head bolts have been tightened

Tools: feeler gauge

1. Adjust after first 50 hours, then every 600 hours.
2. Do adjustment with engine cold and not running; remove rocker arm cover.
3. Turn engine by hand until valves rock, then one more full turn.
4. Loosen lock nut and adjust clearance with adjustment screw.
5. Set both intake and exhaust to 0.006-0.010 in (0.15-0.25 mm).
6. Repeat for each cylinder and replace rocker arm cover.

1. Press belt with thumb at midpoint between crankshaft and alternator pulleys.
2. Tension is correct when belt depresses about 3/8 inch (10-15 mm).

Tools: thickness gauge, wrench

1. Readjust valve clearance after first 50 hours of operation; adjust valves every 600 hours thereafter.
2. Do adjustment after cylinder head bolts have been re-tightened; engine should be cold and not running.
3. Remove the rocker arm cover.
4. Turn engine by hand until inlet valve starts to open and exhaust valve starts to close (valves rocking), then turn crankshaft one more full turn and adjust clearance on both valves for this cylinder.
5. Insert thickness gauge between rocker arm and valve cap; loosen lock nut and adjust with adjustment screw.
6. Clearance on both intake and exhaust valves should be 0.006 - 0.010 in. (0.15 - 0.25 mm).
7. Repeat for each cylinder.
8. Replace the rocker arm cover.

⚠ Make absolutely sure no impurities enter the engine while changing the element.

⚠ Do not run the engine with the air cleaner removed.

1. Check dust trap on bottom of air cleaner daily; squeeze rubber cap lips to let dirt fall out.
2. Visually inspect air cleaner every 100 hours; check more often in dusty conditions.
3. An element cannot be cleaned; replace dirty elements when necessary.

⚠ Escaping diesel fuel under pressure can penetrate skin and cause serious injury

⚠ Use cardboard or wood, not hands, to search for leaks

1. Loosen bleed screw on top of fuel filter.
2. Pump hand primer on fuel lift pump until pure fuel with no bubbles escapes.
3. Tighten bleed screw.
4. Loosen bleed screw on injection pump, pump primer until bubble-free, tighten.
5. If engine will not start, loosen a fuel line at the injector and crank until pure fuel escapes.

1. First 100 hours on a new or reconditioned engine are critical to life and performance.
2. Constantly check engine temperature and oil pressure gauges.
3. Oil consumption is greater during break-in as piston rings take time to seat.
4. Change engine oil and filter at 50 hours.
5. Change oil and filter again at 100 hours.
6. Retighten head bolts at 50 hours.
7. Maintain at least a 75% load for the first 100 hours; if not possible, no less than 50% load.
8. Vary the load to help seat the rings.

⚠ Overtightening can damage the filter housing.

⚠ Do not use a wrench to tighten the filter.

Tools: filter wrench

1. Use a filter wrench to remove old filter; dispose of filter in approved manner.
2. Make sure gasket from old filter is removed and discarded; clean mount face.
3. Spread a thin film of engine oil on the new filter rubber gasket.
4. Screw filter on nipple until gasket meets the sealing surface.
5. Tighten filter one-half turn farther using hands only.
6. Fill engine with recommended oil.
7. Start engine and check for leakage.
8. Stop engine, wait 3 minutes, and check oil level; add oil if necessary.

⚠ Overtightening can damage filter housing

⚠ Never use a flushing oil

Tools: filter wrench

1. Loosen plug in oil pan and drain oil; dispose of waste oil properly.
2. Remove old filter with a filter wrench; discard old gasket.
3. Clean mount face and oil the new filter gasket.
4. Screw filter on until gasket meets sealing surface, then 1/2 turn by hand.
5. Fill engine with recommended oil.
6. Start engine, check for leakage, stop, wait 3 minutes, check level.

1. Flush the cooling system every 600 hours or every 12 months, whichever comes first.
2. Remove radiator cap and open drains on radiator and engine block.
3. Pour clean water into radiator until water coming from radiator is clear of discoloration.
4. Close radiator drain and continue flushing until water from engine drain is clear.
5. Open all drains and drain engine and radiator completely.
6. Close drains and refill radiator with recommended coolant mixture (50% water / 50% ethylene glycol antifreeze).
7. Check hoses and connections and repair any leakage.
8. Start engine and check for leaks; run engine for five minutes, then shut it down.
9. Let engine cool, then check coolant level and add as needed.

⚠ Allow engine to cool before working on cooling system

⚠ Open filler cap carefully using protective clothing

1. Flush every 600 hours or every 12 months, whichever comes first.
2. Remove radiator cap and open radiator and engine block drains.
3. Flush until water from both drains is clear of discoloration.
4. Drain completely and refill with recommended coolant mixture.
5. Check hoses and connections and repair any leakage.
6. Start engine, run 5 minutes, shut down, let cool, check coolant level.

⚠ Do not run engine with air cleaner removed

⚠ Ensure no impurities enter engine while changing element

1. Check dust trap daily; squeeze rubber cap lips to empty dirt.
2. Visually inspect air cleaner every 100 hours.
3. Replace element when necessary; an element cannot be cleaned.

⚠ Store the set in a dry, protected place

1. Drain and flush radiator and cooling system; leave dry or refill with antifreeze mixture.
2. Fill fuel tank or add biocide per manufacturer instructions.
3. Seal air cleaner inlet, exhaust opening, crankcase breather pipe and fuel tank vent.
4. Change crankcase oil and filter.
5. Loosen the alternator belt.
6. Disconnect and clean battery; remove to warm storage if possible.
7. Clean outside of unit and put corrosion preventative on exposed metal.