Yanmar 4TNV98-GGE Engine

1. Check V-belt tension and wear every 50 hours.
2. Press belt with thumb at midpoint between crankshaft and alternator pulleys.
3. Correct deflection is about 10-14 mm at point A, 7-10 mm at point B, and 9-13 mm at point C for a belt run more than 5 minutes.
4. Loosen bolt in tensioning arm and move alternator to tighten belt.
5. If belt is replaced, run engine 5 minutes and re-adjust if needed.

⚠ Apply oil to contact surface between adjusting screw and push rod.

Tools: thickness gauge, wrench

1. Adjust valve clearance every 1000 hours or once a year when engine is cold and not running.
2. Remove rocker arm cover.
3. Turn crankshaft clockwise to No. 1 cylinder compression TDC; pulley top mark at zero on timing scale.
4. Insert thickness gauge between rocker arm and valve bridge; record clearance.
5. Loosen locknut and adjusting screw; set clearance to 0.006-.01 in. (0.15-0.25 mm).
6. Adjust No. 3, then No. 4, then No. 2 cylinders; turn crankshaft 180 degrees each time.
7. For 4-valve head, push bridge so two valve stem heads contact uniformly; adjust bolt so gap becomes 0; tighten locknut.

Tools: DC test bulb

1. Remove power wire from heater terminal.
2. Connect DC test bulb between positive battery terminal and heater terminal.
3. If bulb lights, heater is functioning; if not, replace heater elements.

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

1. Check dust trap daily; squeeze rubber cap lips to let dirt fall out.
2. Visually inspect air cleaner every 250 hours; check more often in dusty conditions.
3. Replace dirty elements; outer element part #24-28503, inner element part #24-28504.
4. Ensure no impurities enter engine; do not run engine with air cleaner removed.

⚠ Escaping diesel fuel under pressure can penetrate skin; seek medical attention immediately if injured.

Tools: cardboard or wood

1. Loosen bleed screw on top of fuel filter.
2. Pump hand primer on fuel lift pump until pure fuel without bubbles escapes; tighten bleed screw.
3. Loosen bleed screw on injection pump; pump until pure fuel escapes; tighten bleed screw.
4. If engine does not start, loosen one fuel line at injector while cranking until pure fuel escapes; tighten.
5. After engine starts, use cardboard to check for fuel leaks; do not use hands.

⚠ Dispose of waste oil in an approved manner.

Tools: filter wrench

1. Change engine oil and filter after first 50 hours.
2. Use Service CC 30 weight oil during first 100 hours.
3. Change oil and filter again at 100 hours, then every 250 hours.
4. During intermittent cold weather, change oil every 100 hours or six weeks, whichever comes first.
5. Warm engine but do not overheat; drain oil from oil pan plug into a basin.
6. Replace lube oil filter; remove old gasket, clean mount face, oil new gasket, install hand-tight plus one-half turn.
7. Refill with recommended oil; capacity with new filter is 11.1 quarts (10.5 liters).
8. Start and check for leaks; stop, wait 3 minutes, and check oil level.

⚠ Allow engine to cool before working on cooling system; open filler cap carefully.

1. Flush cooling system every 2000 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 from radiator drain is clear.
4. Close radiator drain and continue flushing until water from engine drain is clear.
5. Drain engine and radiator completely; close drains and refill with 50% water / 50% ethylene glycol antifreeze.
6. Check hoses and connections and repair any leakage.
7. Start engine for five minutes, shut down, let cool, then check coolant level and add as needed.

Tools: torque wrench

1. Tighten bolts when engine is cold.
2. Loosen nuts and remove rocker arm cover.
3. Tighten head bolts with torque wrench in the order shown in Figure 9.
4. Tighten evenly in 2 or 3 passes, ending at specified torque in final pass.
5. Replace rocker arm cover.

1. Drain and flush radiator and cooling system; leave dry or refill with antifreeze-water mixture.
2. Fill fuel tank or add biocide per manufacturer's instructions.
3. Seal air cleaner inlet, exhaust opening, crankcase breather pipe, and fuel tank vent with plastic bags and tape.
4. Change crankcase oil and filter.
5. Loosen alternator belt.
6. Disconnect and clean battery; remove to warm storage if possible.
7. Clean outside of unit; paint scratched surfaces and apply corrosion preventative to exposed metal.
8. Store set in dry, protected place; cover if stored outside.

⚠ Use protective clothing and open filler cap carefully when engine is warm.

1. Check radiator water level; when cold it should be about 1 in. (2.5 cm) below the filler cap sealing surface.
2. Check crankcase oil level with dipstick; maintain between high and low marks.
3. Check fuel tank level and open fuel valves at tank and secondary fuel filter.
4. Turn on any optional battery switch that may have been installed.

⚠ If gauges deviate from normal levels, shut down the generator set and investigate.

1. Check gauges often.
2. Oil pressure must be above 15 PSI.
3. DC voltmeter should read between 11 and 15 volts at 80°F (25°C) ambient temperature.
4. Water temperature gauge must be below 200°F (94°C).
5. Run unloaded for a three to five minute warm-up period, then add electrical load.

⚠ Do not hold the preheat switch too long; it can burn out glow plugs or heater elements.

1. Hold Shutdown Bypass-Preheat switch ON for 10 to 20 seconds before starting a cold engine.
2. While holding Shutdown Bypass-Preheat switch ON, push Engine Control switch to START.
3. Release both switches as soon as the engine starts.
4. Do not crank starter more than 20 seconds consecutively; ensure engine has stopped before re-engaging.