Flooding occurs due to an improper way of starting your chainsaw. The step-by-step guide to starting the MS 291 will most likely resolve the issue of flooding. If it doesn’t, you’ll want to get your saw checked at the STIHL dealer. Specifically, the main cause of the flooding is when you pull the starter chord several times even when the saw is in the full choke position. When in full choke position, to increase the ignition chances, more fuel than air is passes into the combustion chamber. Repeated pulling of the rope can thus cause flooding. To prevent this, if your chainsaw doesn’t fire even after several pulling of the rope in the full-choke position, you can go ahead and move the lever to an open-choke position so that less fuel and more air will flow into the chamber to balance it out. This will start the engine and solve the problem.