Northern Lights — Injector Removal and Installation

Repair & overhaul · Fuel injectors

From a Northern Lights owner's manual covering: M20C, M844, M844L, OM844K2, SP5, SP6. Check it applies to your exact model before use.

Applies to: Northern Lights M20C, Northern Lights M844, Northern Lights M844L

Procedure

1. Clean loose dirt from around the injectors and the fuel lines.
2. Relieve high pressure by loosening the delivery line flare nuts at each injector.
3. Remove delivery lines as an assembly; do not remove the spacers. Cover the ends of the lines, injector inlets and injection pump outlets.
4. Remove the return line retaining bolts and remove the return line.
5. Unscrew and remove the injectors.
6. Discard the copper sealing washers from the injector hole in the head; cover holes to prevent dirt entering the cylinders.
7. Install a new copper sealing washer in each injector hole.
8. Screw in injector and tighten to 44 - 51 ft/lbs (6 to 7 kgm).
9. Install return line using a new sealing washer below each connection; tighten retaining bolts to 22 - 30 ft/lbs.
10. Install delivery lines, leaving them loose at injectors for bleeding.
11. Crank engine to fill lines; tighten lines at injectors to 11-18 ft./lbs. Start engine and check for leaks using paper or cardboard.

Full service-parts list: Northern Lights M20C →, Northern Lights M844 →, Northern Lights M844L →

Source: Northern Lights owner's 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.

More Northern Lights repair guides →