http://jetsrus.com/FAQ_mikuni_vs_dyn...ihin_sizes.htm

 

Personal experience is they don't cross anywhere near like those charts. Things may have changed since those charts have been copied and pasted for years now. The small rounds we use in our cvk carbs seem to follow right in step with the dj. For example, the chart shows a dj 136 the same as a K 148, but in reality the 136 is noticeably leaner as measured with a sniffer on the dyno.

 

Interesting, the DJ jets I have seem to be made of pretty soft stuff. I noticed that the ones I have had loose in a tool box on my bike have worn the numbers off from shaking around with some spare carb screws etc. My guess would be that the kiehn jets are probably better quality metal, and also more constant from a sizing standpoint. I looked at a few different charts on the net and there do seem to be some discrepancies.
Makes it harder to sort the jetting out.

 

red, I'm not sure you can judge the material hardness of the DJ or any jet in those shake-and-bake conditions. All of these jets are brass and quite soft from my experience. Also, I have a decent handful of Keihin jets and a few DJ jets. I used my jet drill index bits to check sizing difference. I had a 150 Keihin and DJ main jet, and they checked out to be identical to the drill index. Isn't there more than one Keihin main jet design? Which makes me wonder which Keihin main jet they might be comparing on this list.

 

Good points. I have ordered a 138 and 140 and 142 K main jet and a 38 and 40 pilot, as well as a Kouba. My jetting was pretty darn good and then I cut the backfire screen out and I seem to be bogging in the mid range. I am going to lift the needle a notch and if that doesn't do it I will try a 140 K main which is either a 128 or 130 or so DJ.
I am nearly three turns out on the stock pilot wih a 128 DJ main and three notches on the needle.

 

I moved the needle up one notch to the fourth and the bike runs much better. It has a higher top end speed and pulls fairly well through fourth gear.
I am going to go up a size on the pilot and main jet when they come in and see what happens.

 

You should always get the main jet right first, then go backwards from there. Once you change the main, everything else will change, then you'll have to go back, and do it all over again.

 

Yes, I changed the needle position because I could do it easily.