Hercules — Fuel Injection Pump Installation and Timing
Repair & overhaul · fuel system
From a Hercules service manual covering: D-1500, D-1700, D-2000, D-2300, D-3400, De3000. Check it applies to your exact model before use.
Applies to: Hercules D Series engine
Before you start
- Do not rotate the pump shaft backwards to align internal timing marks.
Procedure
- Rotate crankshaft to align flywheel at proper before top dead center degree mark of timed cylinder on compression stroke.
- Remove timing hole cover plate; turn rotor in direction of engine rotation so timing lines coincide.
- Install vertically mounted fuel pump: ensure thrust spring and button in drive shaft end, insert pump onto studs, install nuts and washers finger tight, rotate to align timing marks, tighten nuts.
- Install horizontally mounted fuel pump: insert drive shaft into taper of drive gear, install nuts finger tight, install lock washer and nut on drive shaft, rotate until timing marks align, tighten nut
- Install timing cover plate.
- Connect fuel lines using new gaskets; tighten fuel passage bolts to 35 foot-pounds.
- Connect throttle and stop control linkages.
- Open fuel supply, start engine, and check for leaks.
Tools required
- Torque wrench Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Horizontal fuel pump drive shaft nut torque 65 foot-pounds.
- Fuel passage bolts torque 35 foot-pounds.
Source: Hercules service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.