Northern Lights NL498D2 / NL498K2 — Adjust Valve Clearances
Adjustments · Cylinder head valve train
For the Northern Lights NL498D2 / NL498K2, from the Northern Lights operator's manual.
Applies to: Northern Lights NL498D2
Before you start
- Apply oil to contact surface between adjusting screw and push rod.
Procedure
- Adjust valve clearance every 1000 hours or once a year when engine is cold and not running.
- Remove rocker arm cover.
- Turn crankshaft clockwise to No. 1 cylinder compression TDC; pulley top mark at zero on timing scale.
- Insert thickness gauge between rocker arm and valve bridge; record clearance.
- Loosen locknut and adjusting screw; set clearance to 0.006-.01 in. (0.15-0.25 mm).
- Adjust No. 3, then No. 4, then No. 2 cylinders; turn crankshaft 180 degrees each time.
- For 4-valve head, push bridge so two valve stem heads contact uniformly; adjust bolt so gap becomes 0; tighten locknut.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Valve clearance: 0.006 - .01 in. (0.15 - 0.25 mm)
- Firing order: 1 - 3 - 4 - 2
Full service-parts list: Northern Lights NL498D2 →
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.