Needle number for KDX 250

[smaggard]

Hi:

First what a great forum this is! The server sure has been getting a workout with all of my searches :)

I just bought a '93 KDX 250 and am starting to work on it. I've read othe people's setups (MattGts has been extremely helpful).

I've read that I should use an R1367H needle, the stocker is an R1368H.

However every Kehin conversion chart I see, there is NO "H" listed as an OEM L1 measurement. Am I crazy?

If I call someone like MXSouth or Sudco will they be able to get me the right needle withought me figuring out the Kehin part #?

The bike has a DG pipe on it but it clearly wasn't made for it (cable tied, bolt holes don't line up). Matt recomends the Dyno Port and on their website they have it listed for this bike on special for $99!!! But then I call and they say no, it's custom made and it's $229?? They didn't even know the website said that.

So I'll probably just get the Fatty and TC silencer with it.

The current jetting is 38/158 stock needle and slide. Seems sluggish down low, I'm cleaning the carb and checking the float level as I type so that may cure some of it. It culd need a new piston though, not sure when it was done.

Overall it's in good shape though, has Excel's, a steering dampener too. paid $1200, so for a few hundred more I should have decent bike. I'm also ordering a new chain/sprockets, thinking 13/48 does that sound good to start?

This forum is addicting, I've been searching for days before I finally bought the bike.

Sorry for such a long post...it's been brewing for some time! :aj:

peace
Scott

 

[dirt bike dave]

I think you want a leaner needle than stock (1369 or 1370) rather than richer. Also, a leaner slide with 1mm cutaway (or you can grind 1mm off the bottom of your stock slide) is a common mod on the KDX250. The stock jetting on this bike was way off.

Another cheap mod is replace the headgasket with thin one from an '88 KX250 for more compression and low end power. You will need to run pump premium. Many people run a hotter B7ES plug, even with the leaner jetting.

I really enjoyed my '91 - very good bike for the price with a few mods (stock it does not work so well). The bike really benefits from the right jetting, as well as revalving and respringing the forks (they are pretty grim stock).

The bike is heavy for a 250 2 stroke and has slow steering geometry. But the motor is bulletproof and can make decent power. You can't do much about the weight but the bike will turn better if you raise the forks in the triple clamps about 10mm above the top of the clamp. With 13/48 you can take links out of the chain and run the wheel all the way forward in the adjsuters to shorten the wheelbase. I also had no pre-load on my aftermarket fork springs (0.40kg/mm) to allow the front to dive a little on cornering. Cutting some foam from the front of the seat will make it easier to get forward while cornering, even if you are not short (I am 6')

13/48 is good for tight and medium trails. You might prefer 14/48 if you are doing more high speed trails. I had mine dual sported and would run 15/48 on road rides, but you have to remove the case protector for the bigger sprocket.

The motor has good low end and a very heavy flywheel - Jeff Fredette told me they called it the 'four stroke of two strokes'.

Other tidbits: Both mine and my buddies had gas tanks that measured 3.6 gallons (the manual says 3.3). Graphics from an '89-'94 KDX200 will fit with minor trimming (no one sells stickers for a KDX250). As with the 200, the chain guide is wimpy and can bend in the rocks or deep ruts, locking up the wheel. The Fredette Racing Products chain guide is a good investment.

 

[smaggard]

Thanks for the reply and tips Dave!

I can't wait to get it up and running! Not sure if anything has been done to the suspension really. I wonder if the shock has a heavier spring? The side of the shock reservoir says "Factory Connection...where serious riders get tuning" or something like that. I'm wondering if it's aftermarket or just a tuned up stocker. I think I could tell if it was an Ohlins or something.

Maybe I'll wait on the needle until I get the FMF, tuning to this pipe that isn't made for it may just be a waste of time anyways.

Thanks!
Your posts are encouraging, seeing as you loved the bike and all!
peace
Scott

 

[dirt bike dave]

Scott,
Try calling Factory Connection and see if they have any records on the bike. I don't know if they would, but they might. They are an excellent company and my current bike has their suspension, and it is awesome (I had Race Tech front and rear on my KDX250).

The KDX250 was given very bad reviews by the magazines, so it did not sell well. This makes resale values pertty low, so its a great bang for your buck. Basically, the mags did not like the weight, the riding position, the way the motor ran and the overall handling. Fortunately, the motor can be remidied easily, and improving the forks does wonders for the bike's manners.

If you are a magazine guy used to riding MX bikes with 2 gallon tanks for 15 minute motos, a KDX feels wide, but I need to go 60+ miles of range so the big tank works for me.

IMO, Kawasaki was trying to keep the price low and just did not quite finish developing the bike's jetting and suspension like they should have. So its up to the owner to finish the job. In Kawasaki's defense, the bike was sold as a dualsport in some markets, and the soft spring forks with too much high speed compression damping might be the right setup for the street.

I had an FMF pipe on mine, and I also had a modified aftermarket silencer/spark arretor from a KDX200. It worked well, and the power delivery was very smooth, with more rev than the stock pipe and less of a low/mid hit which the stocker has when the jetting is cleaned up.

 

[smaggard]

Thanks again Dave!

I'll look into the factory connection link.

Definitely not a magazine guy...
I actually haven't had a dirt bike since my XR 80 um a long long time ago :yikes:

Last bikes have been street (GSXR's). I finally realized that with laws of physics working against me (200lbs sliding across asphalt at 80mph and $$$ for going down!), might as well give a dirt bike a try again. I've always wanted to get another and just haven't. I reassembled the carb today, cleaned it up, adjusted the floats (they seemed off using the justkdx method) and I think it runs a little better. But I have to take it somewhere to ride as I can't keep screaming around my neighborhood :aj:

Also awaiting my helmet, gear, and chain/sprockets I ordered.

I'll be around here though, this place is great! Searching the forums has so much info it's unreal!

It's defintely different coming from street to dirt without having thrown a leg over a dirt bike in 15 years! So I'll take my time in getting the feel for the bike and all for sure.

One thing I think I said it has a steering dampener but I think it's a stabilizer, WER I think, i saw it in a magazine.

thanks again!

Scott

 

[dirt bike dave]

The WER is a fine unit. I also had one on my KDX250 and my '90 KDX200. The WER will occasionally need service, but steering dampers are one of the greatest innovations in dirt bikes over the last 15 years. That's a nice bonus to get one on a used bike, as sellers usually transfer it to their new machine.

Welcome back to the dirt. It's a great sport.