The Carter 2100s NEVER used the ball and weight; the 2100s ALWAYS used the pointed needle.
If the rebuilding kit contained a ball and weight, then it would be one of the "one size fits all" variety.
The earliest YF carbs DID use the ball and weight, but it was discontinued and replaced by the pointed needle by fall of 1953. The 2100s was released in November 1953.
The headmaster of the Carter carburetor school once told me folks kept losing the weight, and it was replaced by the pointed needle.
But the single piece (pointed needle) has less chance of sticking than the two piece (ball and weight), especially on the later castings that were machine for the pointed needle.
Jon
