KDX stock carb jet needles?

[matt-itude]

I've been reading every thing i can on jet needle selection and what you are all running. I have a 03 KDX 200 with a woods pipe deltaforce3 reed cage stock silencer and the snorkel removed from the air box lid. My ridding starts at about 5000ft and at times peaks over 10000ft. The question I cant seem to solve is when i went with the reeds and pipe I had to jet down on the pilot and main (and it is so sweet) the stock needle (R1174K) translates to a BFQ correct. so why if I went to leaner main and pilot would i go richer on the needle (CEL ,CEK) or am i reading the charts wrong or missing something here? I would like to try a different needle just for the experience but don't want it to get altitude sickness up high in exchange for a little more power at lower elevations.

 

[Green Hornet]

The needle has an effect on the overall operation of the carb. (A mechanic explained this to me) :blah: If your not having any problems and jetting is about dead on I would be careful about changing the needle. I don't think your going to find the power your looking for. IMO

 

[G. Gearloose]

Your both in detention.. your homework . :think:

 

[Green Hornet]

Now teacher I'm just passing what I've been told & tried myself. Screwing with the needle does have an effect from half to full :) Personally if everything is close w/jetting I would leave it. But the HOMEWORK Link is cool. Have your carb mod & that should work-But I'm in detention ;)

 

[G. Gearloose]

you're a good sport...
Just don't exclude yourself from that info just because you don't have the RB carb mod, that thread is a great to understand the needle and how you can run better.

The needle affects a wider range of throttle than I think you realize (yet).

Its helpful to show the printable version, make a hard copy then read it in full (multiple times) and keep for your records.

 

[matt-itude]

Thanks a ton for the link! This is exactly the kind of info ive been lookoing for. It actually talks a fair amount about stock carbs and slides in there too. thanks again!

 

[Rhodester]

The (a) short answer is that even though a 'C' or a 'D' needle can have a richer 'L1' (narrower diameter) the straight section (L1) is longer than on the 'B' needle (ie. the tapered section starts farther down the needle). That's why a 'B' needle with a fatter (leaner) L1 can act richer then a 'C' or 'D' (with a narrower L1) if it's run in a rich clip position (4 or 5) when running it in a just off idle throttle position. I run a DEK/3 (with a #7 slide...I'd need a DEL for a #6 slide and a DEM for the stock #5 slide) for strong bottom end acceleration. If I want a little smoother bottom I would run a CEK. This will work well at any elevation. If you set your pilot for the middle of your riding elevation you'll possibly only need to change it for extreme temperature variation. The air screw can usually handle any needed pilot mixture changes that way. That leaves the main jet. You'll of course need to change it for major temperature or elevation changes, but it is set up on the carb so as to accommodate quick and easy changes.

 

[Green Hornet]

Yeah, What he said

 

[Rhodester]

.....in other words....once you get your jetting set up you may never need to change the needle or pilot...just the main jet. Now don't that sound easy?

 

[matt-itude]

I am very thankful Rhodester!!! This is exactly what I needed. Now I have a good base knowledge and a starting point. I'll now order some needles and check it out. Thanks again.

 

[matt-itude]

So the delivery curve on the stock needle is lean? this is what im understanding from whats said and the charts ive seen. Moving to these needles will put me several steps richer in thase areas correct?