All C&S custom carburetors are factory set to the usual settings for the intended application. Normal starting point on idle screws is one turn out.

The following tuning information will not be needed if the standard settings are correct for the customer's motor.

The idle and throttle response adjustment of the C&S product is much greater than a stock carb.

Install carb on motor and bring engine up to operating temperature (at least 180 degrees F).

Check fuel level in float bowl. Float level is preset at factory, but will be affected by fuel pressure of customers motor. Correct setting with motor running is fuel should barely run out of sight plug hole on side of float bowl. To adjust, loosen slotted screw slightly on top of float bowl, then turn nut clockwise to lower level and of course, counter clockwise to raise level. One flat on nut (1/6 turn) will raise or lower fuel level 1/32 of an inch so less than one full turn will bring fuel to proper level. A shop towel around nut will catch any fuel that squirts out.

Don’t skip this adjustment. Fuel level affects main circuit startup and has a small effect on wide open throttle air/fuel ratio. On rare occasions a slightly higher or lower setting will solve problems. But, unless you are an expert tuner, stick with the standard setting. It will almost always result in greater performance.

You are now ready to tune idle/transition settings.

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