So an old thread re-surfaced and reminded me of some needle work (ahem) that I was doing a while back. I've measured most of the carb needles available to suit NC30 carbs (HRC and OE). I've just re-discovered the data, so I'll slowly put it all together and post it here as I go. So in the end we should have a collection of profiles for all the different needles in one spot.
I know that personally, my needle choice comes down to seat of pants testing and what others are running. But if we know the needle profile and how that affects fuelling, we should be able make a more educated choice rather than guess with trial and error (i.e. turn these measurements into something qualitative). Calling all tech heads
So to kick off, here's a comparison of one of the standard NC30 needles (J51B) and a HRC SS needle (8ZF). There is only a very slight difference in base diameter between the two. There is an obvious difference in length. But the key difference is in the tapers - 8ZF will run noticibly richer than the stock needle.
