Generac MFH500 Generator Set

⚠ Asphyxiation. Running engines produce carbon monoxide.

1. Position the unit on a flat, level surface.
2. Position the unit a minimum of 5 ft (1.5 m) from structures or barricades.
3. Verify exhaust vapors or fumes will not enter buildings or enclosed areas.
4. Place wheel chocks as required. Do not position on a grade or slope.
5. Verify the unit is uncoupled from the tow vehicle before operation.

⚠ Personal injury. Excessive weight. Use only appropriate lifting equipment.

Tools: Forklift

1. Verify the lifting equipment is suitable for the load.
2. Insert the forklift prongs into the forklift pockets on the unit.
3. Raise the unit a small distance and assess stability.
4. Continue lifting to the desired height once stability is established.

⚠ Risk of burns. Do not open coolant system until engine has completely cooled.

1. Verify the engine is stopped and cooled.
2. Remove radiator cap.
3. Fill the radiator slowly with coolant until it reaches the filler neck.
4. Operate the engine approximately five minutes at a low idle speed to bleed air.
5. Stop the engine, allow it to cool, and add coolant as needed.

⚠ Equipment damage. Do not make battery connections in reverse.

1. Replace the battery with one of equivalent size, voltage, and CCA.
2. Fill a new battery with the proper electrolyte and fully charge it before install.
3. Connect the red battery cable from the starter contactor to the positive (+) battery post.
4. Connect the black battery cable to the negative (-) battery post.

1. Verify that the engine is stopped and cannot be operated.
2. Apply 22 lb (98 N) thumb pressure at the midway point between the alternator pulley and the idler pulley.
3. Read the belt tension.
4. Replace the alternator drive belt if it is out of spec or damaged; replace belts as a set.

⚠ Electrical shock. Disconnect battery ground terminal before working on battery or battery wires.

1. Verify battery cable connections are not loose or corroded.
2. Verify battery electrolyte level is sufficient; replenish with distilled water if necessary.

⚠ Risk of burns. Do not open coolant system until engine has completely cooled.

1. Remove radiator fill cap.
2. Check coolant level and degree of fouling.
3. Install radiator cap securely.

⚠ Engine damage. Verify proper type and quantity of engine oil prior to starting engine.

Tools: Oil dipstick, Clean lint-free cloth

1. Remove oil dipstick and wipe it dry with a clean, lint-free cloth.
2. Slowly insert the clean dipstick fully into the oil dipstick tube.
3. After 10 seconds, remove the dipstick and read both sides; the lower reading is correct.
4. Oil level must be between the MAX and MIN marks.
5. Add oil if necessary; run the engine one minute, wait 10 minutes, and recheck.

1. Verify hydraulic oil level is between MIN and MAX on the hydraulic oil level gauge.
2. If below MIN, add hydraulic oil through the hydraulic fluid fill port.

⚠ Risk of burns. Allow engine to cool before draining oil or coolant.

⚠ Drain one fluid at a time.

Tools: Suitable container

1. Verify unit is off and interior components are cool.
2. Verify all ball valves are closed.
3. Place a suitable container under the exterior drain port.
4. Remove the plug from the exterior drain port.
5. Open the ball valve for the fluid being changed.
6. Allow fluid to drain.
7. Close the ball valve and install the exterior drain plug.
8. On the controller, reset the service interval.

⚠ Only perform this procedure once unit has cooled.

Tools: Suitable container

1. Locate the threaded plug at the front and underneath the unit.
2. Place a suitable container below the threaded plug.
3. Remove the threaded plug and drain the fluid into the container.
4. Insert and tighten the threaded plug once draining has stopped.
5. Dispose of the fluid according to local, state, or national regulations.

Tools: Funnel (optional), Oil dipstick

1. Verify the oil drain valve has been closed.
2. Remove the oil dipstick before adding oil.
3. Wipe the area around the oil filler cap clean.
4. Remove the oil filler cap.
5. Fill the engine oil pan with fresh oil through the oil filler port; do not overfill.
6. Wait 15 minutes for oil to reach the oil pan.
7. Check the oil level with the oil dipstick.