Generac Quietpact 40G (Gasoline) / 40LP (LP Vapor) Repair & Troubleshooting Guide

**TEST 2: CHECK & ADJUST ENGINE GOVERNOR**

**Discussion:**
Rotor operating speed and AC output frequency are directly proportional. This generator is designed to deliver a frequency of 60 Hertz at 3600 Rotor rpm or 62 Hertz at 3720 Rotor rpm (Page 36). The Voltage Regulator is adjusted to deliver 120 VAC (line-to-neutral) at 60 Hertz or 124 VAC (line-to-neutral) at 62 Hertz (Page 36). Because these are linked, if the governed speed is high or low, the AC frequency and voltage will be correspondingly high or low. The no-load governed speed is typically set to 62 Hertz to prevent excessive droop under heavy electrical loading (Page 36).

**Governor Static Adjustment Procedure:**
1. Loosen the GOVERNOR CLAMP BOLT (Page 36).
2. Push the spring end of the GOVERNOR LEVER clockwise to the wide-open throttle (WOT) position (Page 36).
3. While holding the lever at WOT, use pliers to rotate the GOVERNOR SHAFT fully clockwise (CW). Use minimum force against the shaft (Page 36).
4. Maintain the GOVERNOR SHAFT at fully clockwise and the GOVERNOR LEVER at WOT, then tighten the GOVERNOR CLAMP BOLT to 70 inch-pounds (8 N-m) (Page 36). Note: The Torque Specifications table lists a Governor Lever Pinch Bolt torque of 108 in-lbs (Page 91); however, the procedure specifies 70 inch-pounds (Page 36).

**Governor Dynamic Adjustment Procedure:**
1. Start the engine and allow it to stabilize and warm up at no-load (Page 36).
2. Turn the ADJUSTER NUT until the frequency reading is 62 Hertz (Page 36).
3. Verify the GOVERNOR SPRING is properly located in the correct slot of the GOVERNOR LEVER as shown in Figure 7-1 (Page 36).
4. If the spring was repositioned, recheck the frequency and readjust the ADJUSTER NUT to maintain 62 Hertz at no-load (Page 36).
5. Once no-load frequency is set, check the AC voltage (Page 36).

**Branching Results and Next Steps:**
* **Condition A:** If the frequency is correct but you have low or residual AC voltage: **GO TO PROBLEM 2** (Page 36).
* **Condition B:** If no-load frequency and voltage are correct, but they drop excessively when loaded: **GO TO PROBLEM 4** (Page 36).
* *Reference:* Loaded frequency (100% LOAD) should be 57–60 Hz and Loaded voltage (100% LOAD) should be 112.5–116.5 VAC (Page 90).
* **Condition C:** If frequency is correct but no-load voltage remains high: **GO TO VOLTAGE REGULATOR ADJUSTMENT, PAGE 9** (Page 36).

**Technical Specifications for Verification:**
* **Operating Speed:** 3600 rpm (Page 90).
* **Rated Volts:** 120 VAC (Page 90).
* **Spark Plug Gap:** 0.03 inch (Page 90).
* **Stator Power Windings 11 & 22 / 33 & 44 Resistance:** 0.468–0.542 ohm (Page 90).
* **Rotor Winding Slip Ring to Slip Ring Resistance:** 12.72–14.73 ohms (Page 90).
* **Excitation "DPE" Winding Lead 2 to 6 Resistance:** 2.168–2.51 ohm (Page 90).

**Summary Recommendation:**
Perform a static governor synchronization and dynamic adjustment to 62 Hertz at no-load before proceeding to voltage regulator or internal alternator diagnostics.