Generac — Adjusting No-Load Frequency (Q-40G, NP-66G/LP, Q-55G/LP, Q-70G/LP)
Adjustments · Governor
From a Generac service manual covering: NP-50G, NP-50LP, NP-66G/LP, Q-40G, Q-55G/LP, Q-70G/LP. Check it applies to your exact model before use.
Applies to: Generac NP-50G, Generac NP-50LP, Generac Q-40G, Generac NP-50G/LP engine
Before you start
- Avoid overspeeding the engine.
Procedure
- Loosen governor clamp nut.
- Push spring end of governor lever all the way up to wide open throttle position.
- Hold governor lever at wide open throttle. Insert screwdriver into slotted end of governor shaft. Rotate governor shaft fully counterclockwise.
- While holding governor shaft fully counterclockwise and lever at wide open throttle, tighten governor clamp nut to 70 inch-pounds (8 N-m).
- Start engine, let it stabilize and warm up at no-load.
- Turn adjuster nut to obtain frequency reading of 62 Hertz.
- Check governor spring location. Move spring left on bracket teeth for excessive droop; right for greater stability.
- After repositioning spring, recheck frequency and readjust adjuster nut if necessary.
- Check AC voltage reading. If incorrect, voltage regulator may require adjustment.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 70 inch-pounds (8 N-m)
- 62 Hertz
Full service-parts list: Generac NP-50G →, Generac NP-50LP →, Generac Q-40G →
Source: Generac service 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.