4 Things to Know About Adjusting a Chainsaw for High Altitude

Turn the high-speed screw clockwise to lean the mixture At higher altitudes, thinner air makes the engine run rich. Turning the H screw clockwise reduces fuel flow to compensate.

Adjust in small increments per 1000 feet of elevation Turn the screw about 1/8 turn for every 1000 feet gained. Make adjustments while the saw is running and cutting under load.

Listen for a clean four-stroke sound that clears when revving The goal is a smooth idle that transitions cleanly to full throttle. Over-leaning can seize the engine.

Check for EPA limiters or non-adjustable carbs first Many newer saws have fixed jets or limiters. You may need a different jet or professional service instead of a screw adjustment.