Generac 9735 Generator Set

1. Turn the two adjusting cap screws to change drive belt tension.
2. Adjust until the compressed length of the two belt tension springs is 5/8 inch (16 mm).
3. Turn the adjusting bolts to set the four lower bearing carrier springs to a compressed length of 7/8 inch (22 mm).

Tools: wrenches

1. Turn two adjusting bolts until compressed length of springs is 5/8 inch (16mm).
2. To adjust four lower bearing carrier springs, turn adjusting bolts to obtain compressed spring length of 7/8 inch (22mm).

Tools: AC frequency meter

1. Loosen the governor lever clamp bolt.
2. Hold governor lever at full INC RPM position and rotate governor shaft clockwise fully.
3. Tighten governor lever clamp bolt to 70 inch-pounds (8 N-m).
4. Connect an AC frequency meter across generator AC output leads.
5. Turn off all loads; start the engine and let it warm up.
6. Check frequency: 61.5-63.5 Hertz (60 Hz units) or 50.5-51.5 Hertz (50 Hz units).
7. Turn the speed adjust nut until correct frequency is obtained.
8. If frequency is unstable, turn carburetor idle jet until engine stabilizes.
9. Apply load near maximum rated wattage; adjust idle jet for best operation and highest rpm.
10. For adjustable main jet, loosen locknut and turn main jet counterclockwise until frequency drops.
11. Turn main jet clockwise until frequency drops again.
12. Turn main jet counterclockwise to obtain best and most stable frequency.
13. Hold the adjustment and tighten the main jet locknut.
14. Turn off loads and repeat.

⚠ Failure to do the static governor adjustment before starting could cause overspeeding, engine damage, personal injury or property damage.

⚠ All linkage MUST be installed to make this adjustment.

Tools: AC frequency meter, torque wrench, M6 crows foot wrench

1. For gasoline, turn idle mixture valve clockwise until lightly seated; do not force.
2. Turn idle mixture valve counterclockwise 1-1/4 turns.
3. For gaseous, turn idle and slotted adjustments clockwise until softly seated.
4. Turn both adjustments counterclockwise 1-1/2 turns for 6600, 7000, 7200 watt models.
5. Turn both counterclockwise 2 turns for 5000, 5200, 5500 watt models; tighten load block lock nut.
6. Loosen the governor clamp nut.
7. Push governor lever to wide open throttle; do not bend the lever.
8. Hold lever wide open and rotate governor shaft counterclockwise as far as it will go.
9. Tighten governor clamp nut to 70 inch-pounds (8 N-m).
10. Connect an accurate AC frequency meter to generator AC output leads.
11. Start engine, let it stabilize and warm up at no load.
12. Turn adjuster nut to obtain 62 Hertz (60 Hz units) or 51 Hertz (50 Hz units).
13. Apply load near full rated capacity; note frequency droop and hunting.
14. If frequency droops below 58 Hertz, move governor spring closer to anti-lash spring.
15. Readjust and repeat until no-load speed correct and no excessive droop or hunting.

⚠ Static governor adjustment must be made before engine start to prevent overspeed

Tools: torque wrench, frequency meter, screwdriver

1. Adjust carburetor: turn idle mixture valve clockwise to seat, then counterclockwise 1-1/4 turns.
2. For gaseous fuel, adjust load block: turn idle and slotted adjustments clockwise to seat; for 6600-7200W turn CCW 1-1/2 turns; for 5000-5500W turn CCW 2 turns.
3. Static governor: loosen governor clamp nut.
4. Push governor lever to wide open throttle.
5. Rotate governor shaft counterclockwise as far as it will go.
6. Tighten governor clamp nut to 70 inch-pounds (8 N-m).
7. Start engine and adjust to 62 Hz no-load for 60 Hz units.
8. Apply load and adjust governor spring to prevent droop below 58 Hz.

Tools: AC voltmeter, AC frequency meter

1. Perform Test 3, the Fixed Excitation Test.
2. Adjust the voltage adjust potentiometer only while the unit runs at correct governed no-load speed.
3. Set no-load frequency to about 61-63 Hertz; AC output voltage should be about 122-126 VAC.

Tools: VOM

1. Check engine oil level; replenish if necessary.
2. Remove protective boot from switch terminal.
3. Disconnect wires from switch terminal.
4. Set VOM to Rx1 scale and zero.
5. Connect meter across switch terminal and frame ground with engine shut down; should read continuity.
6. Crank engine; oil pressure should open switch; meter should read infinity.
7. Hold Wire 85 to frame ground; engine should shut down.

⚠ Do not connect other end of positive jumper until ready

Tools: 12 volt battery, jumper wires, AC voltmeter or VOM

1. Disconnect Wires No. 4 and 0K from Voltage Regulator.
2. Connect jumper from battery positive to Wire No. 4.
3. Connect jumper from battery negative to Wire No. 0K.
4. Connect AC voltmeter across generator AC output leads.
5. Start engine, let stabilize.
6. Connect positive jumper to Wire No. 4.
7. Read AC voltage; should be about 45-55 percent of rated voltage.
8. Stop engine and reconnect Wires 4 and 0K.

Tools: VOM, thermometer, heat source

1. Remove Wire 85 from switch terminal and try start.
2. Remove switch and place sensing tip in oil.
3. Place thermometer in oil.
4. Connect VOM across switch terminals; should read infinity.
5. Heat oil to 260-270°F (128-130°C); contacts should close and meter should read continuity.

⚠ Do not exceed 1000 volts and do not apply voltage longer than 1 second.

Tools: megohmmeter

1. Disconnect wires from the rotor brushes or remove the brush holders with brushes.
2. Connect the positive test lead to the positive slip ring (nearest the rotor bearing).
3. Connect the negative test lead to a clean frame ground such as the rotor shaft.
4. Apply 1000 volts; do not apply voltage longer than one second.
5. If breakdown indicated, clean and dry the rotor then repeat; replace rotor if it fails the second test.

⚠ Do not apply voltage longer than one second.

⚠ Do not connect tester leads to any leads routed into the generator control panel.

Tools: megohmmeter or hi-pot tester

1. Disconnect and isolate all stator leads.
2. Connect the terminal ends of all stator leads together.
3. Connect tester leads across all stator leads and to frame ground on the stator can.
4. Apply a voltage of 1500 volts; do not apply longer than one second.
5. If breakdown indicated, clean, dry and re-test; replace stator if it fails the second test.
6. Also test between isolated windings and between parallel windings at 1500 volts.

⚠ Storage batteries give off explosive hydrogen gas

⚠ Battery electrolyte is caustic sulfuric acid

Tools: Automotive type battery hydrometer

1. Once weekly inspect battery posts and cables for tightness and corrosion.
2. Clean and/or tighten as necessary.
3. Check battery fluid level and fill with distilled water only.
4. Every six months have state of charge and condition checked with an automotive hydrometer.