My Keihin carb on my 220 has a needle with five grooved clip positions. My question is this:

When comparing an 1172 needle with an 1173 needle, would it be safe to say that an 1172 with the clip in the top groove is still richer than an 1173 needle with the clip in the bottom groove?

bump...I know that someone out there knows the progression of settings. I changed my needle and went with the leaner 1173 and just experimented by putting the clip in the middle position. I'll keep experimenting. Just was looking for someone to validate my reasoning. Next time I go riding I'll take note of how the performance changed. I was getting some heavy exhaust smoke and spooge was spitting out of the pipe.

I don't know what those numbers mean but some needles are just a half of a goove different and others change the taper of the needle. Without knowing which of those changes are on those needles it's hard to awnser your question...again, not being familiar with those neeedles.

no, not at all. Checking the charts now, and there's only the slightest difference between 1172 and 1173 needles. Not even half a clip position worth. Running both needles in the same clip position and the 1172 has just a tiny bit more fuel flow from 0 - 3/16ths throttle. The peak of this increase is a bout 2% @ 1/16th throttle, tapering to 0% at 3/16th throttle. After that point the fuel curve is identical between the two needles all the way to WOT.

These are Kawasaki designated needles. I think officially they are 1172L and 1173L. The larger number indicates a larger diameter needle. I think the L indicates the taper and the 11 indicates the lengths of the straight portion of the needle up by the grooves. I think the only difference in these two needles is the diameter. A fatter needle will allow less fuel to get by and thus lean out the mixture. But changing the clip position may allow the needles to overlap the range of this mixture change.

Yes, I know this. The kawi KDX needles are r1172n/r1173n. For these needles, the R11 is the taper, the 72/73 is the diameter, and the N is the L1 length.

R1173n needle is a equivalent to a keihin BGP, and the r1172n needle is equivalent to a BGN needle. A small change in diameter will only really affect fuel flow over the straight section of the needle, which is roughly 1/4 throttle or less.

Here's the relative fuel change when going from 1173n to 1172n needle, using same pilot/main and 5th clip position. As you can see, the difference is not what you might think it should be...

So, dropping the pilot jet might give me the more leaner mixture that I am seeking.

Indeed. Let me know your current jetting and we'll do some comparisons.

Oh, while we're on the subject, might I suggest a cek/dek needle? You'll need to go down on the jetting considerably to compensate for the richer needle, but the fuel curve with these needles is overall much better than the 1172/73 kawi needles. What year is your bike? I forgot....

97 KDX 220, stock pipe, boyesen reeds. 42 Pilot, 145 main, now 1173 needle, middle groove clip. I've already purchased a 40 pilot in anticipation. Also a 38. Also picked up 142 and 140 mains. Near Chicago...600 feet above sea level.

wow. I would think that jetting would be pretty close at that elevation. What oil are you running, and at what ratio? What's the condition of the bottom end? Are you sure both main seals are good? Top end is in good condition and providing good compression? Forgive me if we've gone over this stuff at another time, my short term memory is for crap these days....