Northern Lights — Injector removal (SP11)

Repair & overhaul · fuel injectors

From a Northern Lights owner's manual covering: 643/673, M643, M673, NL643, NL673. Check it applies to your exact model before use.

Applies to: Northern Lights M643, Northern Lights M673, Northern Lights NL643, Northern Lights NL673, Northern Lights L643 / L673 engine

Procedure

1. Clean loose dirt from around the injectors and fuel lines.
2. Relieve high pressure by loosening delivery line flare nuts at each injector.
3. Remove delivery lines as an assembly; do not remove the spacers; cover all open ends.
4. Remove the return line retaining bolts and the return line.
5. Unscrew and remove the injectors; do not use pry bars.
6. Discard the copper sealing washers from the injector holes and cover the holes.

Full service-parts list: Northern Lights M643 →, Northern Lights M673 →, Northern Lights NL643 →, Northern Lights NL673 →

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 →