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One thing I am still having a hard time deciphering is needle codes. The L1 part being 2.??? is where I can't seem to get past. Maybe we could sticky this in an appropriate section of the site if it attracts enough interest. If someone with the patience and time could give us (me) a beginners guide to the differences in the needles (DEL,DEK,CEL,CEK ETC ETC) it would be hugely appreciated and hopefully stop my silly questions... OK well some of them anyway. Due to my banishment from DRN I can't access CC and others info on this which I had bookmarked to review when my brain could compute it, I think it's ready for some learnin'... Again CHEERS everyone for contributing to making our KDXperiences even more fun and satisfying.

Take a CEK as an example:

C= actual TAPER which is measured in degrees. The quicker (more degrees) the taper is the faster it richens as it is pulled up out of the main jet. Most felt at 1/4 to 3/4 throttle. D would be quicker, richer or more taper.

E= The length of L1 (distance from clip to start of taper). This is also controlled by the clip position as stated by the -3 as middle, -1 as top, -5 being bottom position. Raise the clip lowers the needle which means the throttle must be moved more before the taper portion is exposed in the main jet and comes into play. If I am not mistaken, think of an E needle as being the 3rd (center) clip position. The next higher position (2) would be F and the highest (1) would be G. Most felt at 1/4 to 1/2 throttle. G would be leaner or longer, B would be richer or shorter.

K= Diameter. This is the maximum diameter where the needle sits in the main jet. The smaller the diameter the richer the circuit. Most felt at idle to 1/4 throttle. L would be larger or leaner, J would be smaller or richer.

DISCLAIMER: until CC puts his 2 cents on this answer, disregard.

You are absolutely correct!! Well...except in the place you aren't...quite.

The L1 is a bit different than 'to the start of the taper'.

Also commonly a reason for confusion in understanding needles.

THe L1 is not the distance from the clip to the start of the taper.

L1 is the distance from the clip-end of the needle (I'm sure that's what bradf meant..not the clip but the clip end..the blunt end! ;) ) to the point where the needle diameter is 2.515mm. That number is generally referred to as the 'magic number'.

You can see there will be considerable difference between the taper start and the point at which the magic number happens with different angles of taper and starting diameters.

Where this is important: Consider two different taper º with the same L1 and diameter. The faster taper will get to 2.515mm sooner than the slower taper, so the faster taper needle will have to START tapering LATER (further from the blunt end) than the slower taper needle.

Cool, huh?

You can see that the taper hit in throttle position will change with a change of needle angle and the same L1. That's why (fer instance) a common clip position for the DEK is -4.

A slower taper needle can be somewhat richer toward the bottom of the throttle.

Now class...why is that?

Not that it matters a whole lot...but you know the angle numbers? They are measured in degrees and minutes. Each º is made up of 60 equal parts called 'minutes.' For example, a 'B' needle taper is listed as 1º15' (that would be 1 1/4º) a 'C' needle is 1º34' (that would be 1 1/2º).

Yeah...each minute consists of 60 equal parts called 'seconds' too...

Doesn't seem like much...but figure the % of change and then it is clearly quite a large difference (20% change from a 'B' to a 'C')

Howwzat?

Oh...I do expect correct answers on the above taper question.

What does it all mean CC?

What can be expected from each of the different measurements. Say... I have a CEK... and I want it to hit harder on the bottom...What should I be looking at and why?

The graph you're used to seeing as far as what works where generally answers your question as long as you keep in mind there is a lot of overlap in the different circuits...it's not a marked black-and-white thing.

A 'hit' isn't usually a good thing. It is generally a recovery of the carb FROM a throttle position that wasn't working correctly. I've run jetsets (in combination with some reed setups) that have a heckuva kick real low. It stinks! I could be on just a bit of a hill, try to pick up the front end to clear an upcoming root and loop the thing! Couldn't keep the front wheel on the ground!

No thanks!

You want (I'd think) a smooth, strong, sure power delivery over the throttle range. Sure, the KIPS transition is something you will feel, you'll feel the pipe when it comes into its tune, too.

There's a hint on JD's tuning guide about changing needles...I don't have it on this machine..remind me if I don't get it posted here tomorrow.

I don't know enough about it to tell you exactly what you have to do to get 'X'. A better response on the bottom will come from a richer straight and a later starting taper.....which is what the CEK does. The oem needle is as I recall a BEQ or so. The 'K' is quite a bit richer than the 'Q' diameter..and the 'C' taper starts later than the 'B', so you're on the straight (the real straight...not the L1 so called 'straight') longer.

The RB carb came with an AEN at one time. Man...that was BAD!!! You'd be 4-stroking something awful after a just a teeny downhill/idle time. It was all because of the taper start..real early in the case of the 'A' needle.

From the needles I've tried, I'd say the CEK is about as rowdy as you can get (with a #7TV), hit-wise. In my bike on -4 it was a real handful!! Fun, but not nearly as useful as the 'D' taper. Couldn't climb much of anything without looping the thing. I'm no hillclimber...I need all the help I can get!!

The point is to understand how the taper comes into play..how an earlier start/later start makes a difference in your bike. If you think the L1 is to the START of the taper...none of it makes any sense at all!!

I didn't mean it literally... Just for example. I would like a copy of that chart too, Someone really needs to put it into simple terms.... such as... this does this (a graph would be really helpful) It's weird that this has not been done before. But I'm sure it would have to be bike specific since there are such a wide range of Jetting differences between the models.

CC - The hint on JD's spreadsheet associated with changing needles is to keep the 1/4 to 3/8 fuel curve cross over point about the same when switching needles.

Thanks alot guys. I will print this out and study it and hopefully my dumba$$ will be able to grasp the theory, but I doubt it so I will probably return in a few days with all these dumb questions. You have been prewarned... Thanks again...

IC says it right.

Note that JD has the CEK as one of his picks for the PWK. The DEK is in the richer end of mid-throttle things.

His PWK info of course doesn't include bored/plated carbs....