Jetting my 03 KDX200

[TVRider]

I finally got someplace I could do a WOT plug chop. Attached is a picture of the plug after 5th gear uphill WOT for 20-30 seconds.

My '03 200 has FMF woods, Airbox lid removed, VForce DII with high tension setting, 155 main, 42 pilot, airscrew 3/4 turn, needle clip at #2. Temp. 50, low humidity, at or near sealevle. I am trying to attach a picture of the plug. This is my first time trying this so bear with me.

How does this look? CC or Rich?

Thanks,

Tom

 

[TVRider]

Anyone? Just looking for some help here.

 

[23jayhawk]

Did that plug have any run time before the WFO blast?

 

[canyncarvr]

Your pic is a bit small...and making it larger just pixelates the heck out of it. How does it compare to the following?

I've attached a shot from RR, about which he says:
"The plug INSULATORS look dramatically different but the jetting is pretty much spot-on in both cases."
(the second plug he's referring to obviously not shown in this thread. Go HERE to see the whole story.

The band on your plug looks a bit wide to me.

Compare the two plugs and see what you think. As RR says: "It's worth the effort but I can tell you after peering at plugs for 30 or so years I still have more questions than answers most days."

Anecdotally, (and therefore mostly useless) I am running 40-152-CEK/4-#7TV, but that's with the KG-30! That pipe takes a considerably richer jetset than the KG-35 does. That setup is good to about 50º, 2000-4500'el.

Point is, besides the band looking wide (that's what you're after...the width of the band at the bottom of the insulator), I'd WAG from your jet list that you're still rich some.

 

[TVRider]

23Jayhawk,

The plug was brand new. I got the bike good and warm, went to the base of the hill I was doing the WOT plug chop on, change to the new plug, fired her up and went wot thru the 1st 5 gears. Maintained it in 5th for about 20-30 seconds.

CC,

I have read that thread you referred me to 2 or 3 times all the way through. That was why I was looking for input. My mixture ring is 4 to 5 times as tall as the picture you posted from the other thread and not near as dark. I didn't know what to think because my mixture ring was much lighter. After rereading that thread again, I see it is the height of the mixture ring that is signifigant. I will try a smaller mainjet and test again. Thanks for the help.

 

[canyncarvr]

I figured you had read that thread, actually. Didn't mean to imply u-b-slackin' on research! ;)

Anyway, you know then that the plug shown has 12 track laps on it. Considerably more than one WOT chop test. Hence the lighter part of the ring on your plug. But, yes...it's the 'thickness' or depth of it that's the issue.

Recall 1mm being stated in that thread as about right.

A BTW...if RR took a look at the jetting on my bike, he'd likely laugh hisself silly. I've never taken the time to get my bike 'spot on'. I'm not anal about jetting, but I DO pay attention to weather, riding conditions and bike config (say, pipe changes for a big example). I have made good use of JD's spreadsheet to research needle choices. I've gone from the gurgling blubbering plug fouling mess that is oem jetting to never-miss-a-beat with my RB carb. The RB carb didn't start out that way!! It was quite a few steps to where it sits now. Now, I can ride all day, go downhill as long as I want, idle forever and still never get a single 4-stroking burp. AND the kdx can keep real close to a particular orange 200exc (in certain conditions. Put us on technical single track and he disappears!)! That's a good running kdx!

Point is I'm not comfortable seeing any reference to myself and RR in the same sentence. He's forgotten more about this stuff than I'll ever know.

Still, with a little input here and a little input there, I hope you get to a satisfactory conclusion.

You're on the right track.

Cheers!

 

[TVRider]

CC,

I didn't think you were calling me a slacker, not that you wouldn't if it was true :laugh:. I'm glad you posted the link because I needed to read it again! It makes a world of difference when you're holding your own plug in your hand and reading at the same time. When I really open the KDX up it seems to be lacking energy on top, I guess that's the jetting being too rich. I'll experiment some more and post results. Thanks for the help and thanks to all the other DRN KDXer's. I don't know much about this stuff but I learn everyday! :thumb:

 

[canyncarvr]

Not to change the subject....but to change the subject....;)

Part of the 'weak on top' is the kg-35.

You might try a different needle, too. A CEL would be something to try with the oem #5 slide.

Tell 'ya what...send me your address and I'll send you a CEL. Well...if I still have one, and I'm pretty sure I have TWO of 'em.

Start on #3. Give #4 a shot, too.

Let me know.

Another subject change...what's your air filter situation? Using the oem filter?

A twinair will work better (more air). AND run leaner (less pressure differential). A notoil filter is cheaper and likely more commonly available at your local bike shop. Similar to the twinair. I prefer the twinair.

What's your filter oiling procedure? If it's soaking it, then 'removing the excess', you're using too much oil.

Either of which will add to the 'weak on top' too.

 

[TVRider]

Thanks! I'll PM you with my address. Just to make sure I've got it right, the clip at the top of the needle would be #1 then on down for 2,3, etc?

I have the stock air filter and use the UNI foam filter cleaner and oil. I have seen twinair mentioned and was thinking about trying one. I'm lucky, Motorcycle Stuff (you may have heard of them), is headquartered right here in river city, so I can get most none oem parts same day or next day. :yeehaw:

 

[canyncarvr]

'Top' being the blunt end....where the clip slots are.

Got your addy. I'll try to get my single brain cell to rememmer to bring the needle(s) in and ship them tomorrow.

Consider using notoil. Its ease of use may bring about increased frequency of use. That would be good. ;)

 

[toalco-kdx]

Originally posted by canyncarvr

You might try a different needle, too. A CEL would be something to try with the oem #5 slide.

whats the differnece between a CEL needel and a regular one? its supposed to add more power right? i heard about them but i forgot the name and i was gonna try to get one.

 

[23jayhawk]

The key differences are in the first and last letter. The stock needle on a 200 is a BFQ. The first letter is the taper of the needle, with the C taper being steeper than the B. The effect of a steeper taper is that it 'comes on' harder as you transition past 1/4 throttle. The last letter is the straight diameter of the needle, with the Q being just about the leanest (largest diameter) needle available. The diameter seems to have the most effect between just off idle and maybe 1/3 throttle.

I've tried a few of the more common options over the winter, and finally settled on a BEM. The smaller M diameter helped eliminate an annoying off-idle bog that seems to plague a KDX when it's jetted down close to right. Not that mine is perfect, but it's certainly not rich. But it gives a certain crispness that I really like at small throttle openings, when you're trying  to get over loose rocks and such.

I've tried a couple of C taper needles (CEM, CCN) and they were just a bit sudden for my riding conditions and ability. In the rocks around here, I really like the smooth, almost electric transition of the B taper. Others have found that a C taper works well with the -30 pipe; they seem to compliment each other.

Keep in mind that I'm a C-Senior rider; better riders tend to like a harder hit from what I've seen, since things are happening at a faster rate for them.

 

[canyncarvr]

There is a needle decoder write up on CDave's site.

Bet'cha can't guess where you might find that link.


I give up...

Read the 'Every kdx rider should read...' thread that is stuck to the top of this forum. The link is in FredT's post.

Print some of the charts. Make some notes. Read the archived 'RB carb' thread and pay particular attention to JD's input.

..and I don't recall the stock 200 needle directly crossing to any keihin needle. pick pick pick........;)

Cheers!