My generator won't start - Troubleshooting Guide

If your FIRMAN doesn't start when you need it the most... Here are the Troubleshooting Steps to follow!


  • Did you put the FULL bottle of oil in the unit? The low oil sensor will stop the ignition coil from sparking.
  • There is more than 2 gallons of gas in the tank.
  • Go step by steps on how to start the unit following instructions in manual.
  • The battery cables are in good condition and properly connected to the battery. Make sure that the quick connect on the black negative battery cable is connected.
  • The fuel valve is in the “I” position and the ignition switch is in the “I” or ON position (On dual fuel models, the fuel selector knob is the fuel valve)
  • You are choking the unit properly: 1-2 attempts to start with choke in the “START” position and if it does not start then 1-2 attempts with the choke in the “RUN” position
  • The battery is fully charged to at least 12v or higher
  • The spark plug wire is securely connected to the spark plug above the valve cover. You can also take the spark plug out and do a spark test by putting the extremity on the valve cover and pulling the recoil. If the plug doesn’t spark, you can replace it. If the spark plug isn’t the issue, ignition coil could need to be replaced and we could refer you to a certified service center.
  • On HYBRID models, be sure that the propane tank valve is wide open and turn all the way to the left.
    1. Propane is naturally harder to get started than gasoline. If you are having difficulty starting it, hold the start button down and at the same time, move manually the choke from the “START” to the “RUN” position until it kicks over.
    2. On dual fuel inverter models (WHISPER serie), make sure the power cable on the end of the regulator is properly connected. If not, the solenoid will not open on the regulator and allow propane to pass through it. Also, don’t forget to hold down the battery restore switch for 3 seconds.


  • Check all the above.
  • Check the oil level: you need to dip the dipstick, don’t screw it in to see the right level. Add oil if necessary. Don’t forget to do your oil change after the first 25 hours and then every 100 hours. 
  • The air filter is not dirty, clogged or soaked with oil. If it is, the filter will need to be cleaned with warm soapy water and dried up.
  • The spark arrestor on the muffler is not clogged or carbon fouled (it should look like gray colored screen NOT black or brown). If it is black or brown it should be removed and cleaned with a wire brush or blown out with an air compressor.
  • Remove the spark plug and inspect it for:
  1. Cracks
  2. Fouling (black, oily, or sooty deposits on the electrode or ceramic)
  3. A “pinging” noise if shaken
If any of the above are present the spark plug needs to be replaced
  • The gasoline in the unit is no more than 1 month old (87 octane gas starts to sediment as soon as 2-3 weeks depending on oxygen and moisture exposure)
  • If the gas has been sitting in the unit more than 1 month, It has more than likely clogged the carburetor jets or emulsion tube. To solve this, disassemble the carburetor and soak the parts in good fresh gasoline for 1 hour and the thoroughly spray out all orifices of the carburetor with carb cleaner. Contact Tech Support for additional information.


1. Battery is connected + restore switch battery has been hold for 3 secs on Inverters.

2. Make sure the start switch is not bad

  • To test this, remove the control panel to expose the backside of the start switch.
  • Remove the wires on the backside of the switch and touch them together.
  • If the unit starts then it is a bad start switch that needs to be replaced.
3. The start solenoid is not stuck
  • Follow the battery cables to the cylindrical start solenoid, peel back the rubber boots on the terminals of the solenoid and bridge the terminals with a rubber handled screwdriver.
  • If the unit turns over or starts when bridging the terminals, the start solenoid is bad and needs to be replaced
  • If it does nothing, then the battery is not supplying enough voltage to turn the starter motor and needs to charged or replaced.


  • Make sure you bought the FIRMAN Natural Gas from our Website (10ft or 25ft available). The hose has to be 1/2 inch hose with a 3/8 female flare on the generator side.
  • Please keep in mind these requirements. Max of 101 000 BTU's. Psi needs to be between 0.25 and 0.40.

Hope this guide is helpful, you should print it or have it ready and handy for any situation! And don't hesitate to call our Great Technical Support available in English, French and Spanish at 844-347-6261 or