Nice little technical question for Cope that may help a few people sort their jetting, me included

How does the code for the taper of the needle work

My carb came fitted with a JJH neeedle fitted & a spare JJF for fine tuning

I have a printout here that talks about a few different setups with the needles being LJJ, LJH, JJH, JJJ & JFH, not sure where it came from

My thoughts are that an brief explaination of where in the opening each has the most effect & which way the numbering system works could help with setting up these carbs & their cousins

Edited November 1, 200916 yr by tony27

A quick search and Voila- I think what you want is right after the kawasaki part number info.

http://justkdx.dirtrider.net/jetneedles.html

Try this to explain the dimensional differences , all in the diameter , length and taper.

Needle chart

I would stick with the jjh, but you canevan become a test pilot if you like! Combinations are baffling!

AND fo rthose that think I am mad insisting upon dual vents, try looking at THIS

Edited November 1, 200916 yr by copemech

Hmmm.....

Looks a mess...but who knows....might be worth it on a Keihin....Although god knows how much fuel would pour out of those horizontal vents the way they are set up at the moment.

I think one would have a hard time doing this, like this, to an OKO

Best of balance.

Neo

Edited November 1, 200916 yr by Neo

Thanks guys

From what I can work out there the JJF needle is .03mm smaller meaning it should be richer, not sure why it turned up in #4 position from the top & the JJH was #3

Will have a play before the trial today & see what the effect of the 2 needles are.

May end up swapping back to the dellorto for the day if I can't get things better, can stop the motor if I give it a handful from idle. Lean maybe? No pinging though