You can kick till the cows come home but a dirty carburetor is no match for the strongest leg or even an electric start.
A dirty, gummed-up carb on a 2-stroke or non-fuel injected 4-stroke dirt bike or ATV prevents fuel from reaching the engine causing the no-start or if you're lucky and get the engine started, it sputters and quickly dies thereafter. The same also happens with a dirty air filter but instead of inadequate fuel the clogged filter prevents the correct amount of air into the engine.
Therefore, when experiencing these symptoms first check the air filter before tackling the bigger carb cleaning project. A bike that sits for long periods or uses ethanol based-fuels tends to eventually have problems with the carb. It's a good idea to use high quality gas and ride regularly or use a treatment like Stabil when leaving fuel in the tank long term.
Nevertheless, a carburetor eventually requires cleaning so if you want to stay on top of the process take it apart once a year if you can't use non-ethanol fuel (hard to come by in certain areas) or every few years if pumping race gas and riding regularly. Sorry, no easy way out, either. You can add all the available fuel cleaning additives but it's just money down the drain, or perhaps down the fuel intake. Once dirty, the carb remains dirty until cleaned.
Cleaning the carb on your dirt bike or ATV is a pretty straight forward task but requires disassembly. Grab a carburetor rebuild kit if replacing a number of internal damaged or worn out components or go the OEM route for individual pieces.
First turn the petcock off and remove the fuel hose. Expect some residual fuel in the bowl. You can burn this fuel before disassembly only if it's a routine clean job. Some float bowls include a drain to remove excess fuel specifically for disassembling the carb. This drain includes a vent line so just throw a pan underneath the bike and catch the fuel. Otherwise, if the carb is so dirty you can't start the engine to burn the excess fuel then you'll have to deal with the leftover gas.
Take the carburetor off the bike and if you're new to the scene get a service manual to help guide you through the process. You'll remove a number of parts and components that if we covered here you'd likely tune out after 30 seconds.
Once you've removed the carburetor clean the outside thoroughly first. This removes dirt and oil that could contaminate the inside during the reassembly process. Now disassemble the carburetor; it's ready for cleaning.
Use carb cleaner, and a wire brush helps if it's significantly tarnished. Clean all the jets and use a piece of wire or compressed air to blow any remnants out. Inspect the rubber O-rings for damage but it's probably best to replace anyway. Ethanol eats these like candy but even if you've used only high quality fuel and it's time to clean the carb, pop on some fresh rings. Don't use cleaner on the accelerator pump diaphragm or the diaphragm in the air cut-off valve. Inspect these diaphragms for any damage and replace if necessary.
After cleaning and replacing any necessary internal parts reassemble the carb and install on the bike. Attach the fuel line and turn the petcock on. Start the bike. You're ready to ride.
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Written By: AndrewT