This is done by turning the air screw in either direction, depending on the engines response. Chain filing isnt a difficult task and is crucial in maintaining your chainsaw. Check inside the fuel tank for dirt and debris. This dirt and debris can build up and create a clog. Stihl ST251C Chainsaw Stalls when I depress the throttle. California. A thick fuel mixture can cause excessive carbon around the spark plug, which can even kill a chainsaw. The answer is simple; you check your chainsaws owners manual. Move the piston up in bore a bit more so we can see the piston below the ring and turn your flash off. Secure your chainsaw to maintain stability while working. If the problems remain, examine the fuel lines and carburetor. The carburetor might need: A clean-up if it's clogged. We and our partners use data for Personalised ads and content, ad and content measurement, audience insights and product development. In that case, its best to check your air filter and clean it if needed before moving on to more complex issues. I have replaced the spark plug (properly gapped), rebuilt the carb, replaced the fuel line and the fuel filter, cleaned out the chain brake and the clutch and cleaned the fuel tank air pressure stabilizing valve. The ignition system is essentially a spark plug. Start the chainsaw for a few seconds to make sure the carburetor is functioning correctly.if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[320,50],'remodelormove_com-large-leaderboard-2','ezslot_10',158,'0','0'])};__ez_fad_position('div-gpt-ad-remodelormove_com-large-leaderboard-2-0'); To unclog a chainsaw carburetor, youll need to thoroughly clean the carburetor and replace the air filter.