The term “flooded engine” means that the engine has too much fuel and the fuel has fouled the spark plugs, making it very difficult to start or not working at all.
It is very easy to clean a flooded engine. Just raise the warm-up lever (fast idle, throttle arm) as high as possible and crank the engine without choke. By doing this, it supplies a large amount of air to the engine, which basically removes the extra fuel and cleans the spark plugs, allowing them to restart and start the engine.
Different engines have different ways of activating the heating lever; some have a separate lever for the main control arm. Some engines have a button on the control arm that you press so that you can accelerate the engine in neutral, some engines have to pull the control arm out to disengage the shift lever. Find out how your control arm works and have fun.
Run the engine (make sure it is in the water or with flushing hoses) and keep the choke on until it shuts off (either by pressing the key or holding the choke switch). This will flood the engine. To make sure it’s really flooded; Hold down the choke and try to turn it on, it should be impossible to start!
Now just go full throttle on the warm-up lever, and WITHOUT choke start the engine … It may take a few seconds or several tries, but it will start. Once on, keep the heat lever up until the engine runs smoothly. Be careful not to over-speed the engine. You may need to lower the heat lever to keep the RPM below about 2000 rpm. It will be very smoky for a while.
It’s a good idea to practice different ways of starting the engine in different scenarios, just in case. You never know that one day you might be drifting towards the rocks and in a panic you forget that your engine is already hot and you don’t need to suffocate, if you drown a hot engine it is very easy to flood it. Practice flooding it and trying to relight it, one day it might save you …