New to me KDX220

[ccain85]

I just recently purchased a 2002 KDX220. This is my first time owning a 2 stroke. All of my other bikes have been 4 strokes. I know from research that these bikes are a little more mellow compared to other 2 strokes. Obviously I am very unfamiliar with these bikes and the way they deliver there power. After riding it around a bit ive noticed that running through the gears it really flattens out on the top end. Im currently running FMF Gnarly pipe,snorkle removed, 145 main jet and 42 pilot jet. I am also running 40:1 mix. I would think that it would be able to do some decent power wheelies but it just doesnt seem like the power is there. Is there some tuning I need to do and maybe some untapped power im missing out on?

[bergilong]

These bikes are really mellow. It should have low-mid range power. That gnarly pipe is also made for midrange. My 200 has an FMF fatty and it's still not a beast in the top end.

[thirdgenlxi]

Welcome! Congrats on the new bike You aren't by chance the guy that just bought the 220 from a guy over by Statesville, NC, are you? lol. Had one posted in our local group a couple days ago and a couple of the guys were interested in it, but it sold later that same day it was posted there (to somebody else)

But yea....these bikes def are very mellow. They're more about the bottom end torque than anything..... more of a low revving tractor type motor (which is awesome in the tight gnarly stuff). I always describe it as a diesel dirt bike, lol. One thing to keep in mind though, the 220's used a smaller carb than the 200 (33mm vs 35), in an effort to add even more bottom end, but it also sacrifices some top end. A lot of people either swap a 200 carb onto the 220's, or just bore out the 220 carb. RB and a few others do some pretty sweet carb mods, along with head mods as well.... all of which can wake them up a lot

I assume you do know about the 220 stock pistons as well, right? Just want to make sure....

[ccain85]

I guess I'm so used to riding 250 4 strokes. No actually I do not know about the stock piston.

[thirdgenlxi]

The KDX actually has a powerband similar to that of a 4 stroke.... it still has a 'hit', but not the hard on/off hit like most other 2 strokes. It's very linear and smooth. It's not a fire breathing dragon, but it'll climb up anything and not bog down, won't stall out, no drama, no fuss.... it just goes. If in doubt though you may want to check and make sure your power valve is working properly.... sometimes they can get gunked up and stick either open or closed. Certain pre-mix oils aren't good for power valves and can make them stick, and buying a used bike you don't always know what was run in it before. There's a little round cover on the left side of the cylinder, with a slot in it for a flathead screwdriver.... you can take that off and see the KIPS shaft gear there. Start the bike up and let it warm up real good, then slowly but steadily rev it up and the gear should rotate fairly smoothly to open the valve, and then rotate back shut. It should open right around 6000 RPM. If it's not then something is stuck

And yea the stock 220 pistons had a weird factory defect where over time they would develop a crack that would slowly spread until it broke completely. So if you don't know with absolute certainty that it's had a different piston put in it, put one in it ASAP. Wiseco or whatever.... anything but stock. But once you get that done you're all set with one of the most reliable 2 strokes on the planet. The stock 200 pistons didn't have this problem, only the 220's

[ccain85]

KIPS system is definitely not working. Is there a procedure to clean it?

[ccain85]

KIPS was stuck open and you were right the piston has a small crack in the side skirt.

[CAL-kawi]

Good thing you opened it up! A good thing to do with the new bike regardless, and with a new forged piston in there you'll have some peace of mind.
I'm going to disagree however with the consensus on here that the 220 is a tame lugger. A lugger yes, but if tuned properly there should be plenty up top, maybe not by 250 4t standards but close. Stock needle and pipe change is where I'd start. The stock needle really leans out the upper half of the throttle range and feels flat. Also the gnarly woods doesn't provide much excitement on the 220, unless you're riding boulder fields all day. I've had both the woods and desert pipes on both the 200 and 220, and would go desert on the 220 for best all round performance. A set of cheap boyesen 2 stage reeds without the stock stops will also give more up top.
The 200 works well with multiple setups, even stock. Not the 220, it's really quite amazing the change a few simple changes make on this engine.

[ccain85]

Yeah Im glad too. even though I just bought it 2 days ago and really wanted to ride it. I knew there had to be something wrong when the old 96 XR250 seemed faster than the KDX. The kips system being stuck open must have really robbed the power.

[Dekon]

If the KIPS is stuck open, it will greatly effect the bottom end.

[ccain85]

I serviced the KIPS system and put a new piston and rings in but something still feels off about the power. The XR250R still seems faster and I couldnt even keep up with my brother in law when we would hit a straight section of the fire roads. Ive read that guys are doing wheelies in third when I can barley get the wheel up in first.

[CAL-kawi]

Something is definately wrong then. I had an 02 xr250 years ago, and the 220 should make double the HP if tuned right. Even with the woods pipe and poor jetting it should have slightly more than the XR.

Although they typically are flat right after a new top end. Have you put some time under load at low rpm to properly seat the rings? Also a few heat cycles at lowish rpm (but under good load) are advisable with a forged piston to allow the "grain" of the piston to conform.

Any signs of an air leak? Such as eratic idle, hanging rpms, and bogging.

[ccain85]

I took it out this weekend on some trails to break it in. No signs of auto leak as it seems to idle fine.

[CAL-kawi]

Also good advice from 3rdgen to check under the round cover that the kips is intact and operational. Sounds like the kips maybe not functioning? Did you remember to support the shaft when removing the nut on the kips claw?

[ccain85]

KIPS is working since I cleaned it. I did support the shaft when removing the nut.

[motogoalie1]

Stock pipe? Whats the state of tune, jetting?

These bikes actually haul ass and can hang with anyone if it jetted and set up proper.

[John_S]

You didn't mention the needle that's in it or the needle clip position. That could make a big difference. Sorry to hear you did the top end and It won't wheelie. That's disheartening but something is still way off. Stock carb or 35 air striker my 220 will rip the front wheel up with a 1/4 throttle from idle in 1st (flip over backwards if you don't let off) and wheelie easily in 3rd not even on the pipe. 4th I have to be at the right rpm for a power wheelie but will clutch up wheelie no problem. If I'm standing lugging along 2-3000 rpms in third gear, weight the pegs, and give the throttle a little blip when it deweights it comes up effortlessly. Keep at it because it'll be worth it when the power comes around. The top end overrev is nothing is brag about but it should be hauling ass from idle on up. You just shift a little sooner to keep it in the meat of the powerband. I've ridden an xr250 quite a bit and the 220 should feel like a beast compared to it. Check the timing, the air screw, the needle code and clip position, and number of teeth on the sprockets. Stock is 13/47. I would check all that and start from scratch on the jetting guide.

[John_S]

I never thought I would put this on YouTube but wanted you to see this for comparison. Me talking to myself when I first started to jet my bike. I cut most of it out. One of my only videos with no gloves or boots. The pilot felt pretty good, too rich on the needle, and close on the main. This is with the snorkel on and FMF woods pipe. It should run at least something like this. It runs stronger now with vf3 reeds, no snorkel, and more tuning.

PS that was not 1/8 throttle like I said

[KDXGarage]

put my fat ass on there, cure all that wheelie popping right out.

[John_S]

put my fat ass on there, cure all that wheelie popping right out.

OR...you could hop on the back and we can slow wheelie all the way through a parade. In your hometown, not mine lol.

NOW I realize the OP's last post was 7/10. Did you figure it out ccain?