Carter Carburetor Adjustments
Short answer: The two screws at the front base are the idle mixture screws — out (counter-clockwise) = richer, in = leaner. They only affect idle, not cruise mixture.
Setting them (ideal is an exhaust-gas analyzer, but by ear): with a warm engine, gently seat each screw counting the turns, then back both out to the smaller count. Adjust both 1/2 turn at a time — if it runs rougher you’ve gone too lean, so go back out; keep going for the smoothest idle, then lean it very slightly (back in ~1/2 turn).
Choke: it should just close after a long cool-off in mild weather (more tension in real cold), and be fully open after about 5 minutes of running (no more than 10).
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Content last modified: June 13, 2026 at 10:06 am
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