Excessive smoke and power loss point to an incorrect fuel mixture or an engine running too rich.
- Fuel mix is wrong. This is the most likely cause. You must use a 50:1 mix of high-octane gasoline and a high-quality 2-stroke oil. Using straight gas, the wrong oil, or an incorrect ratio (like 40:1) will cause smoke and damage.
- Air filter is clogged. A dirty filter restricts air, creating a rich, smoky condition. Remove and clean it.
- Carburetor is misadjusted. The high-speed (H) jet may be set too rich. This requires a special tool and should be done by a technician if you're unsure.
IF THAT DIDN'T WORK: The spark arrestor screen in the muffler could be clogged with carbon. This restricts exhaust flow, causing power loss and heat buildup. It needs to be cleaned with a wire brush, but let the muffler cool completely first.
HEADS UP: Never run the saw without the air filter. It protects the engine from debris that causes wear and affects the fuel-air ratio.