Northern Lights — SP-6 Valve Clearance Adjustment
Adjustments · Cylinder head valve train
From a Northern Lights operator's manual covering: M30, M38C3, M38C3F, M40C3F, M944. Check it applies to your exact model before use.
Applies to: Northern Lights M30, Northern Lights M38C3, Northern Lights M38C3F, Northern Lights M40C3F, Northern Lights M944
Procedure
- Readjust valve clearance after first 50 hours; check every 500 hours thereafter.
- Check the valves when the engine is cold.
- Rotate crankshaft clockwise to bring each piston to top dead center on compression stroke in firing order 1-3-4-2.
- Loosen lock nut on adjustment screw and insert feeler gauge between rocker arm and valve stem cap.
- Adjust until feeler gauge slides with slight drag; tighten lock nut and recheck clearance.
- Adjust remaining valves and replace rocker arm cover.
Tools required
- Feeler gauge Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Intake 0.0098 in. (0.25 mm)
- Exhaust 0.0098 in. (0.25 mm)
- Firing order 1-3-4-2
Full service-parts list: Northern Lights M30 →, Northern Lights M38C3 →, Northern Lights M38C3F →, Northern Lights M40C3F →, Northern Lights M944 →
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.