Northern Lights M864 — SP12. Injector Service
Repair & overhaul · Fuel injectors
For the Northern Lights M864, from the Northern Lights owner's manual.
Applies to: Northern Lights M864
Before you start
- Do not use pry bars to remove injectors from the cylinder head.
- Overtightening can damage injectors.
- Do not use your hand to check for leaks.
Procedure
- Clean loose dirt from around the injectors and fuel lines.
- Relieve high pressure by loosening delivery line flare nuts at each injector.
- Remove delivery lines from injectors and injection pump as an assembly; do not remove spacers; cover ends.
- Remove the return line retaining nuts, washers, and return line.
- Loosen and remove the injector; remove the injector seat and cover the holes.
- Take injectors to dealer or injection repair station for testing and service.
- Install new injector seal washer seat and injector; tighten injector to 42-50 ft/lbs (5.8-6.9 k/gm).
- Reinstall return line with new sealing washers; tighten bolts to 18-25 ft/lbs (2.5-3.5 k/gm).
- Reinstall injection lines; tighten flare nuts at pump to 18.2-25.3 ft/lbs; leave loose at injectors for bleeding.
- Bleed lines, crank engine to fill lines, tighten flare nuts at injectors to 18.2-25.3 ft/lbs.
- Start engine and check for leaks using paper or cardboard.
Specs & values
- Injector: 42-50 ft/lbs (5.8-6.9 k/gm)
- Return line bolts: 18-25 ft/lbs (2.5-3.5 k/gm)
- Injection line flare nuts: 18.2-25.3 ft/lbs (2.5-3.5 k/gm)
Full service-parts list: Northern Lights M864 →
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.