PRIMARY FUEL FILTER-WATER DRAIN
See Figure 4-13. If it should become necessary to drain water from the fuel tank, also check the primary fuel filter for water. This can be done as follows:
1. Open the petcock on the top of the primary filter housing.
2. Place a drain pan below the filter and open the petcock on the bottom of the drain assembly. (A length of hose is attached to the petcock to direct drained fluid below the frame.)
3. When all water is drained from the filter, close the petcock lightly.
4. Close upper petcock tightly.
5. Start the engine and let it run briefly. The engine may run roughly for a short time until the air is purged from the system.
6. If engine continues to run roughly, check that both petcocks at the primary filter are closed tightly. The primary filter was used in 1982-83 only.