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I'm new to the KDX, been riding KTM and Husuaberg 300s for years and just got the KDX. It seems to have absolutely no bottom end, makes great power at high revs but don't need that for technical single track trails. Is there something obvious wrong with the bike? or is it I'm just used to the KTM 300 "3 stroke" power?

Should have 3 stroke like power have you messed with the jetting?

The bikes new to me, have only had it on it's first ride. So no I really haven't done anything to it yet.

Jetting & float height
Bad reeds
Powervalve hung open

First 3 things I would check. Shouldnhave a very "electric" powerband, smooth everywhere, and very low end oriented. Similar to a ktm 300, but less power everywhere. Makes a ktm 200 feel really revvy.

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Thanks those are the 3 things I figured I'd start with. Any suggestions on jetting? I'm riding at 3-4000' and probably about 60 degrees. Not to familiar with the kdx power valve any good threads that I should look at? Thanks for the advise.

Hmm a kdx 200 with no bottom end.....?

Should have bought the 220 !!

If the top end has been apart then it would be worth checking the KIPS to make sure the valves are in the correct sides. Some of the repair manuals have them listed backward from what is right.

Found the actuator arm for the power valve wasn't turning at all. Took off the clutch side engine case and found the lever on the bottom of the arm broken off and lying in the bottom of the case. I've not found anyplace that shows me how to put this thing back together once I get the new parts. The Kawasaki shop manual is very vague, Don't know how the top gear or claw is supposed to line up with the gear on the center shaft, etc. etc. Anyone know of a good source for this info? Thanks

it should look like this




so the arm is broken off the actuator (RMATV usually stocks them) and the gear is nicked, I would replace both

silly question, did you turn the actuator arm into this position or was it in mounted like that? (turned about 90 degrees outward)

(edit for explanation) underneath the metal washer the arm sits on (the part that is broken in your pic) are some weights
at about 6000 RPM the centrifugal force of these weights is enough to overcome the strength of the spring that pushes them down and the move up the shaft (the same shaft as the nylon gear is mounted on)
this sideways motion turn the actuator arm which opens the actual valves

That's a bad design. There are many, many other ways they could've actuated that stupid arm. Kawasakis valve system is an excellent design, though. Just a lot of the ancillary parts suck. On a side note: when I got my bike, the kips valve wasn't opening. I checked all parts and they were present and unbroken. I GENTLY turned the gear an could open and close the valves. A visual check showed all valves were functioning as well. I gave up and reassembled my kips- and it has worked fine ever since! Must've had oil residue holding it closed. I've since cleaned it and its fine.

Thanks for the help guys! yes in the picture I took I had already rotated the arm. Now all I need to know is how to position the "claw" on the center shaft gear, seems like there should be some alignment marks or something in the manual like " with valves closed this point on the claw lines up this point on the gear " or is it just kind of foolproof, I know I feel pretty foolish scratching my head looking at this thing. I agree with Actionman, looks like the the valve is a good design but this actuating arm doesn't look to great to me right now.

There is a procedure in the manual that walks you through setting up the exhaust valve. The claw has a mark punched on it that matches up with a mark on the exhaust valve shaft. If you're using an old print manual some of them had the subvalves backwards, but if you have a newer version or the online one it is correct. If you don't have a manual that would be the first money I'd spend. With all that repaired it still doesn't address your initial problem which was no low end. The exhaust valve not functioning would make it flat on the pipe, but not affect the bottom end. If the PO had the top end apart it is possible that they didn't correctly assemble the subvalves (leaving them open when they should be closed) and that would affect bottom end. If the subvalves are in correctly and compression is good then your problem lies elsewhere (air leaks, fuel delivery) A leakdown test will eliminate crank seals and compression issues.

Once you have correctly identified the left and rigt valve it is almost foolproof
On the top of the claw gear is a timing mark that lines up with the mainshaft
then there are timing marks on that shaft and the gear that open the subvalves...which are also marked
Word to the wise: dont worry about getting the timing right on the subvalves and the gears untill the very end...its a pain to drop them in there right but once they are in place you can lift them up and rotate them without moving the gear to get the timing lined up

Thanks again guys! I've got the new parts ordered and I do have what looks like an older manual that I downloaded, Hopefully be out riding it again by next weekend.