It's the muffler. Everyone thinks fuel, carburetor, mixture. They're wrong. The muffler is clogged and the unit can't be tuned to high throttle until you clean it.
Steps: Remove the back housing to access the muffler. You may want to remove the gas tank to avoid a spill. Remove the muffler (2 large screws). Remove the muffler door (3 small screws). The screen should be cleaned using a pin (poke out any hardened material). Most important: The muffler door is 2 parts. Pry it apart and scrape off the burnt carbon that is clogging the exhaust path. Re-assemble and start.
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It's the muffler. Everyone thinks fuel, carburetor, mixture. They're wrong. The muffler is clogged and the unit can't be tuned to high throttle until you clean it.
Steps: Remove the back housing to access the muffler. You may want to remove the gas tank to avoid a spill. Remove the muffler (2 large screws). Remove the muffler door (3 small screws). The screen should be cleaned using a pin (poke out any hardened material). Most important: The muffler door is 2 parts. Pry it apart and scrape off the burnt carbon that is clogging the exhaust path. Re-assemble and start.