Ms391carburetor Disassembly

The most common reason is due to too many attempts trying to start the machine in the choke position. When starting a STIHL chainsaw, make sure to follow the starting instructions in your instruction manual. The manual provides the proper instruction for starting procedures, but there are many conditions that may affect how the unit starts. A good rule of thumb to follow is to remember that when placing the switch control to the full choke setting, more liquid fuel and less air flow into the combustion chamber in order to create a higher chance for ignition. Pulling the rope more than two to three times in this setting may flood the engine. The operator should move the Master Control Lever™ or choke lever from the full choke setting after three to four pulls even if the engine does not fire. Moving the lever to the next setting, the half choke or part throttle position, will allow more air into the combustion chamber and help resolve the flooding condition. The carburetor comes from the factory with a standard setting. This setting provides an optimum fuel-air mixture under most operating conditions. With most carburetors, it is only possible to adjust the engine idle speed within fine limits. Quite often adjusting the carburetor will not solve acceleration issues. To find the correct setting for your machine, please refer to your instruction manual. If you do not have a copy of your instruction manual, please go to our product manual webpage  where you can download a PDF version. Not model specific to model; carb repair video.

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