KDXRIDER.NET

I recently ran across a list of the JD Jetting kits.

There is a kit shown, described as "JD Jet Kit Keihin PWK 38-39 mm 125/200 (99-05)" (JDKH01). Could this refer to a KDX with carb bored out?? Has anyone heard of or tried this kit? Seems that JD's multi-tapered needles could be "the ticket"!

Jeff

P.S. Info. here

Jeff - I think thats for the KTM 125/200's that had 39mm carbs. But i'd imagine that it would be pretty usable on a bored or new 39mm PWK on a KDX.

I think thats for the KTM 125/200's that had 39mm carbs

Ah - that's making sense to me!

Jeff

I attempted to use JDKH-001 kit for a KDX 200, which was one of the first 2 stroke kits that JD put up for sale. (BTW - The 2-Stroke needles were all the same for the kits with the difference in the kits being the main jets and pilots which are included.)

Elevation 5000 and up/ Temperature 60-70.

With a stock 35mm carb and the stock slide cut to approx a 7.1 and a PC2 pipe I could get good performance from 3/8 throttle to WOT with the richer needle in leanest clip position (blue tip ~68 dia straight section) but could not get a clean bottom end even going down to a 35 pilot. Excessive 4 cycling until ~ 3/8 throttle then cleaned up.

Red needle was tried in clip positions 1 and 2 and with various pilots but I was not happy with the snap off of idle. Mid-range was strong but it felt like I transitioned too fast from the pilot to the needle and then when dialing the top end if I jetted the main for the maximium rpm I lost too much of the mid throttle pull.

I contacted JD and asked how the needles compared to the CEK/CEJ needles since I had good results with using those needles. JD said the mid range on the needles would be slightly richer and the top end transition would be slightly leaner.

I have since jetted the new KDX back to the CEJ needle (modified TV) : jetted my oldest boy's '99 KDX with FMF Rev pipe (stock slide) with a CEK needle. My thought is the JD red needle (...69 straight section) will likely work well with a 6.0 - 6.5 slide but will still not compare overall to a CEK due to a trade off in the mid to upper rpm range.

Thanks for the info IC.

-Maurice

'Multi-taper' refers to a double taper needle?

That doesn't fit with what JD told IC (mid-rich/top-lean).

The 38-39mm PWK is not the same body as the 35mm. Don't know what that means from the standpoint of preferred needles. JD hasn't in the past been a huge fan of multi-taper needles..not with the crowd of, 'Multi-tapers are the best for everything!' bunch. The last recs I read from him (couple years back) for the small body PWK (OEM Kawi) were all for single taper needles.

Different subject I 'spose...but I'm curious about 'Excessive 4-cycling', IC. I'd appreciate your input on a separate thread.

Thanks.

CC - yes his needles are double tapered needles.

CC I stand corrected - JD referenced a different needle than the CEK in his response- I was using his spread sheet in an attempt to better dial-in the KDX jetting.

JD wrote:

"The red needle is closer to a DDL or DDM needle at mid-throttle, but then leaner after that. I would have thought the same main jet as CEK 3.5 would be close. I'm not sure which way to go at this point, maybe leaner instead. Try both directions."

This above was in response to one of my questions to him concerning the soft top end on the KDX 200 with a strong mid range and then vice versa when I corrected the MJ for high rpm performance. I was comparing his needle to the CEK 3.5 clip with a given MJ.

CC- I've not ever read anything from JD about mult-taper needles and the 35 mm carb. I just figured that since the two needles that JD developed for the 2-strokes w/PWK carbs covered such a broad range of bikes that I would attempt to see if the needles would work in the KDX 200 with a modified slide.

IC: Didn't mean to imply an inference from multi-tapers to the small body PWK..that I know they stink or anything. Same as you said, 'I've not ever read anything from JD about mult-taper needles and the 35 mm carb.'

Yup. Me too, neither. ;)

I admire the diligence it takes to effectively tune a 2-stroke. I don't have that ability. I DO like the way my bike runs, though. Missing subport drum and all!! THAT oughtta tell 'ya sumthin'!

I'm actually considering defeating the thing permanently!! Hey!! Maybe the new 'next step' in bike modification. BREAK it!!

Yup...I'm in my own SSS, broken KIPS nirvana....

Don't you think not having a subport control drum may be part of he root of your spooz?

I am not bright enough to figure out how it affects the going-ons in the engine. But if it makes you happy and gets you where you want to go then you should be happy.

It spewed before it broke...just not out the RH side of the engine!