Unless the engine is either just rebuilt (less than 500 miles) or almost worn out (burning a significant amount of oil), then 3/4 turn to 1 turn on the idle mixture control screw is a good starting point.

1 1/4 turn will probably SEEM to idle more smoothly, but waste gas at idle, and foul plugs.

Jon.

Good carburetion is fuelish hot air
The most expensive carburetor is the wrong one you attempt to modify.
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