Northern Lights NL673 — Injector Service (SP11)
Repair & overhaul · Fuel injectors
For the Northern Lights NL673, from the Northern Lights owner's manual.
Applies to: Northern Lights NL673
Before you start
- Overtightening can damage injector.
- Do not use pry bars to remove injectors from cylinder head.
Procedure
- Clean loose dirt from around the injectors and fuel lines.
- Relieve high pressure by loosening the delivery line flare nuts at each injector.
- Remove delivery lines by disconnecting from injectors and injection pump; remove as an assembly.
- Remove the return line retaining bolts and the return line.
- Unscrew and remove the injectors; do not use pry bars.
- Discard the copper sealing washers and cover the holes to keep dirt out.
- Install a new copper sealing washer, screw in the injector and tighten to 43 or 50 ft/lbs (6 to 7 kgm).
- Install return line with new copper seals; tighten retaining bolts to 22 - 30 ft/lbs.
Specs & values
- Injector torque 43 or 50 ft/lbs (6 to 7 kgm)
- Return line retaining bolts 22 - 30 ft/lbs
- Check injectors every 1000 hours
Full service-parts list: 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.