In some departments a quick on-scene replacement for a flooded power saw is simply a radio transmission away. Unfortunately for most, this is not the case. Everyone who operates one of these saws should know how to correct this common problem on scene.
When too much fuel and not enough air enter the combustion chamber a machine can flood. The spark plug gets coated with raw fuel and may not ignite. On a properly maintained machine, this can happen if you leave the choke on for too long or if the throttle lock is not engaged while attempting to start. Flooding will not be caused by storing your saw on the rig with the throttle locked and the choke in the on position! Of course there is the ever popular “I left the on/off switch in the off position while trying to start the machine”. Whoops!!!!. If one of these errors occurs, and we catch the mistake in time, you can attempt the following to get the machine running.
Make sure the on/off switch is on. Turn the choke off. Push the decompression valve in. While holding the throttle control in the “full throttle” position, begin to crank the engine over. If the machine starts, hold the throttle control “full throttle” until the machine is running smooth and the excessive exhaust smoke clears up. This is easier with 2 firefighters.
If the machine doesn’t start with the above method, replace the spark plug with the one you should be carrying in your saw kit. This can be done with the combination wrench that your machine comes with. The spark plug, in most cases, is easily accessible so it can be changed fairly quickly. Once changed, attempt to start the machine with the above procedure. If you are trained to use the machine you should know how to change the spark plug.
Here is a video clip on how to change a spark plug on a Husqvarna 960.