So I ran the Y140 needles in my carbs today and they we’re leaner than the stock needle on the pilot jet and middle of the needle. Although as expect richer on the main. I did my runs with it in the middle clip position. Also I was running a 45 pilot, 140 main, and 132.5 air jet. Since my two into one likes the Heiden needle the best I ground off the top clip; so it has some spring action, and raised the needle one more clip. I have a pretty high performance setup and I don’t even think the Y140 needle would help a slightly modified setup. My digital caliper crapped on me or I’d measure the needle. I am assuming it is leaner on the pilot because of diameter at the top. Being a slightly shorter needle than I think I’m safe to say the diameter is also larger in the middle of the needle.
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