Northern Lights M673 / OM673 — Valve clearance adjustment

Adjustments · Engine

For the Northern Lights M673 / OM673, from the Northern Lights operator's manual.

Applies to: Northern Lights M673, Northern Lights OM673

Procedure

1. Engine cold and not running; turn engine by hand.
2. Turn until #1 inlet starts opening and exhaust starts closing.
3. Turn crankshaft one more full turn; adjust both valves.
4. Loosen lock nut; set clearance with adjustment screw.
5. Set intake and exhaust clearance to 0.008 in. (0.2 mm).
6. Repeat for each cylinder individually.
7. Replace rocker cover; tighten nuts to 7.2 - 8.7 ft/lbs.

Full service-parts list: Northern Lights M673 →, Northern Lights OM673 →

Source: Northern Lights operator'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.

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