Generac iQ3500 Engine

Tools: socket, feelers/gauges

1. Verify the piston is at top dead center (TDC) of its compression stroke (both valves closed).
2. Remove four (4) screws from rocker cover.
3. Remove rocker cover and rocker cover gasket.
4. Loosen rocker arm jam nut. Turn adjustment screw in to decrease clearance or out to increase clearance.
5. Hold socket steady and tighten lock nut to specification; check clearance and make minor adjustments.
6. After tightening jam nut, recheck valve clearance to make sure it did not change.
7. Install rocker cover, gasket and four screws; tighten to specifications.

Tools: non-metallic feeler gauge

1. Install or replace trigger pickup; ensure routing of wires is correct and not pinched.
2. With rotor in place, set gap to 0.20-0.30mm using the oval holes in the pickup bracket.
3. Align trigger point on rotor outside surface in-line with sensor and check/adjust gap with a non-metallic feeler gauge.
4. Tighten mounting screws to specification and check gap; adjust if necessary.

⚠ Hold the rocker arm jam nut in place as the pivot ball stud is turned.

Tools: Feeler gauge, 10mm Allen wrench (530cc engine), 13mm Allen wrench (410cc, 990cc, 999cc engines), Large socket and socket wrench

1. Engine should be cool before checking (60° to 80° F / 16° to 27° C).
2. Remove spark plug wires and position them away from the plugs; remove spark plugs.
3. Bring piston to Top Dead Center of its compression stroke (both valves closed).
4. Remove the four screws attaching the valve cover.
5. Loosen the rocker jam nut; turn the pivot ball stud while checking clearance with a feeler gauge.
6. Correct clearance is 0.002-0.004 inch (0.05-0.1 mm).
7. Hold the pivot ball stud and tighten the rocker arm jam nut to 174 in-lbs (19.68 N-m).
8. Recheck valve clearance to make sure it did not change.
9. Install new valve cover gasket and re-attach the valve cover.
10. Install spark plugs and re-attach the spark plug wire.
11. Repeat the process for the other cylinder, if necessary.

Tools: compression gauge

1. Remove spark plug.
2. Insert an automotive type compression gauge into spark plug hole.
3. Crank engine until there is no further increase in pressure; record highest reading.

Tools: Small engine tachometer or inductive tachometer

1. With engine running, connect engine tachometer per manufacturer instructions and record the engine RPM.
2. If engine rpm is within rated specs refer to flow chart; if outside range go to Problem 7 flowchart.

⚠ Explosion and Fire. Fuel and vapors are extremely flammable and explosive. Add fuel in a well ventilated area. Keep fire and spark away.

Tools: suitable fuel container

1. Open side panel to expose carburetor (A) and fuel pump (B).
2. Carefully remove fuel line from filter on inlet side of carburetor.
3. Using a suitable container, slowly pull on recoil cord and turn engine over; fuel should flow from fuel line.
4. If fuel does not flow, verify fuel is available to pump; inspect fuel filter and pulse line.
5. If fuel does not flow, replace fuel pump.

Tools: spark tester

1. Disconnect spark plug lead from spark plug.
2. Attach high tension lead to spark tester terminal.
3. Ground spark tester clamp by attaching to cylinder head.
4. Attempt to pull start engine; if spark jumps tester gap, ignition system is working properly.

⚠ Explosion and Fire. Fuel and vapors are extremely flammable and explosive. Add fuel in a well ventilated area. Keep fire and spark away.

Tools: DMM

1. Stop engine and drain fuel from tank.
2. Remove electrical box assembly, back window, and upper enclosure half.
3. Take out C4 connector (do not remove harness of control panel).
4. Set DMM to measure resistance.
5. On female side of C4, connect one lead to Pin 1 and the other to Pin 4; measure and record resistance.
6. If within specified values refer to flow chart; if outside tolerance replace stator.

⚠ Do not make battery connections in reverse.

Tools: Phillips screwdriver

1. Use a Phillips screwdriver to remove the screw from the battery door.
2. Remove battery strap from battery.
3. Connect red cables to positive (+) battery terminal with bolt and nut.
4. Slide rubber boot over positive (+) terminal.
5. Connect black cables to negative (-) battery terminal with bolt and nut.
6. Slide rubber boot over negative (-) terminal and make sure all connections are secure.

⚠ The exercise timer and current date and time must be reset when the battery is dead or has been disconnected.

1. Verify that utility power is turned off.
2. Check the tag on the engine for oil viscosity and classification; drain and refill if necessary.
3. Check the state of the battery; fill unsealed batteries to proper level with distilled water; recharge to 100%.
4. Clean and wipe down the entire generator.
5. Make sure the 7.5 Amp fuse is removed from the generator Control Panel.
6. Reconnect the battery. Observe battery polarity. Install positive cable first.
7. Reconnect the battery charger AC input T1/Neutral cable (white sleeve) at controller.
8. Open the fuel shutoff valve.
9. Insert the 7.5 Amp fuse into the generator Control Panel.
10. Start the unit by pressing the MANUAL button. Allow the unit to warm up for a few minutes.
11. Stop the unit by pressing the Control Panel OFF button.
12. Turn on the utility power to the transfer switch.
13. Set the Control Panel to AUTO.

⚠ Verify proper type and quantity of engine oil prior to starting engine.

Tools: Funnel

1. Place generator on a level surface.
2. Clean area around oil fill and oil drain plug.
3. Remove oil fill cap and wipe dipstick clean.
4. Insert funnel into oil fill opening and add recommended engine oil.
5. Insert dipstick into oil filler neck to check oil level.
6. Verify oil level is within safe operating range.
7. Install oil fill cap/dipstick and hand-tighten.

⚠ Do not dispose of the battery by incineration.

⚠ Remove the 7.5 Amp fuse from the generator control panel.

⚠ Remove all jewelry and use tools with insulated handles.

1. With the generator shut down, lift the lid and remove the front panel.
2. Inspect the battery posts and cables for tightness and corrosion; tighten and clean as necessary.
3. Check the battery fluid level of unsealed batteries; fill with distilled water only. DO NOT use tap water.
4. Have the Dealer or a qualified Service Technician check the state of charge and condition.