Understanding the needle????

[OldTimer]

I recently posted to another thread in the pit bikes section about needle profiles, but I figure this would be a better place to increase the knowledge base about such a generalized subject, so here's the link:
http://www.dirtrider.net/forums3/showthread.php?t=135801
If you don't want to go through the aforementioned post, my question is about Kehien needles. The carb in question is a PWK28 and comes stock with an NAPE needle.
If you're rich on the needle, wouldn't you want to change the needle jet rather than the needle in order to maintain the throttle curve characteristics? How are the needle jets sized?
If you did want to change the throttle curve characteristics how would you determine which needle to use?
In other words, what do the letters represent: 'N'-'A'-'P'-'E'? :think:

Anyhow, there are a lot of other questions and info in the thread I linked to, so have a look and get back to me....K?

 

[Tdel]

Check out KTMtalk.com in the jetting section there is a sticky on the needle markings and which is richer vs leaner. Also you may want to look into a JD jet kit, I have had excellent experience with them.

 

[Rich Rohrich]

Check out http://justkdx.dirtrider.net/ under the Tech Tips section. Canadian Dave wrote an outstanding article on understanding jet needles.

Here's the direct link : http://justkdx.dirtrider.net/jetneedles.html