Maintenance schedule
| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | Check, clean, replenish oil as frequently as necessary. | — | |||
| Fuel filter | Drain sediment. Repriming required. | — | |||
| Oil filter | Replace the element at time of oil change. Use a Purolator #P-70FF replacement element. | — | |||
| Battery | Fully charge the battery. With the battery still on charge, draw off all the electrolyte above the plates in each cell. Refill each cell with approved water, to the recommended level. Continue charging for 1 hour at a 4 to 6 ampere rate. Test each cell. If the specific gravity is still above 1.225, repeat steps 2,3, and 4 until the reading is reduced to 1.225. | — | |||
| Belt | Inspect and adjust - 1/2 inch play. Use ONLY Onan replacement belt #511P60 (Gates Rubber Co. #8256), except spec A models use 511 3 belt and pulley replacement kit. | — | |||
| Coolant | Check for rust or scale formation. | — | |||
| Oil | Check, replenish as necessary. | — | |||
| Spark plug | Check for proper spray pattern, etc. Refer to the Hercules manual. | — |
Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.