KDXRIDER.NET

Hi!
I got hold a KDX220 recently and upon riding it, it just doesn't seem "right". It doesn't have the power that I'm sure it should have.

Its had a top-end rebuild done with a Wossner forged piston, new gaskets etc. I know this, I'm not just assuming ;)
At first it would struggle to idle by itself with or without choke and also it just wouldn't rev up, even at a standstill, without making alot of smoke. It felt like a serious misfire.

I removed the carb and cleaned it out, although it was pretty spotless to be honest. I read through the jetting guide and set the idle and air screw up, and it now starts alot easier and will idle fine cold or hot. It now also rev's up cleanly at a standstill.

Riding it now seems better BUT it still doesn't have the power. From what I read everywhere if you snap the throttle open in 1st/2nd/3rd it will want to come up, but it just doesn't and feels very flat. Maybe in 1st, but thats it.

I checked the free movement of the KIPS through the round cover and it moves nicely with a socket on. Although after this, I took the cover off with the engine running and revved it, but nothing seemed to move. How high a revs should I need to see some movement?
Also checked the reeds, and they look as new.

I've checked the plug in there and its a dark browny colour, maybe slightly on the rich side but not sooted.

That'll do for now, hopefully someone will have some ideas

The bike is stock with
42 Pilot jet
145 main jet
1173 needle on the middle clip position (I did try slightly richer just to see if it made a difference. Not really....)
Stock exhaust
40:1 premix

Temps are around 8deg C and I'm pretty much at sea level :)

It does not do this:


Although it does turn freely by hand and I can feel it actually opening/closing the valve.

I'm guessing its been assembled wrong inside? Easily done from what I've read

it should do that at 6 K
I don't think you can assemble the KIPS wrong to the point of them not turning
you can assemble them wrong so the timing is off and they will rob the engine of power instead of adding it

like I mentioned in your other thread, check to see the claw gear engages
you might be able to remove just that little cover and run the bike like that to see if it moves but just misses the gear ?
these valves do get gummed up and if neglected that can build up enough junk to prevent them from moving period, but I would double check the pin first

I've just posted my findings in the other thread, thanks for the reply

BUT:

I think this is the problem!!

See the other thread for my findings ;)

Ok, so the pin and screw came today and I set about putting it all back together!

Result!! The KIPS seems to be operating when I rev it up, although not QUITE closing 100% on its own. It looks a little coked up but I'm not too worried at this moment ;)

Definately picks up better now and pulls better, however it doesn't want to lift the front off the throttle if I nail it, in anything other than 1st gear. It may be due to it being pretty slippy and muddy up my road (not been far,just testing it!)

I'm not sure what I should be expecting as I've never ridden a KDX before, and maybe I'm just used to the GSX-R lol

I whipped the plug out also just to check its colour and the tip seems a little on the grey side (lean yes?) but the porcelain part is light brown.

Any pointers on where to go next with it? Does this seem normal for a stock 220?

I'd say that's about right for the 220. Easily pulls the front end in 1st. Lean back and or compression bounce the suspension for 2nd 3rd gear wheelies (depending on rider weight). Also depends on how well you're hooking up. The 220 does not rev as high as one would think, they kinda hit the power ceiling so to speak but they make power all the way to it. I had the same pv issue when I bought mine so I understand what your feeling. I love my 220!

I had fiddle with the air screw following the jetting guide, and it seems the pilot (42) is very rich. The idle kept increasing as I turned the air screw out up to about 6 turns.

Would I be best dropping it to a 40 or maybe a 38? I should be able to get out on a good ride this weekend and see how the plug looks after some miles.

In stock form the 220 is pretty tame but great for tight single track trail riding. It ain't no GSXR, that is for sure.
Its strength is in its torque. A dessert pipe, RBD head, and open up the air box a bit and you remove the as-designed flow restrictions and low compression.
I bet a 40 pilot will help the low end responce and get you really enjoying that torque

Well I've been out today for a few hours and I must say I LOVE IT!
Finally being able to ride it properly and not just "putting about" and it feels good, I see what you mean about the low end torque now!

I need to do some jetting on it though thats for sure. When on <1/4 throttle its very "poppy" and a bit rough, until moving to 1/2-3/4 throttle, then it clears and pulls well :)

Checked the plug after my ride and its running rich on the main as its very dark down inside the threads but the electrode and insulator are a nice tan brown so I happy that its not running lean at least.

I'll get some pilots and mains on order and go from there

I had the chance to have a fiddle with the jets this evening and my god is it better now with a smaller pilot jet and air screw adjusted :)
So much more responsive and not as sloppy and rough at small throttle openings!
I dropped the main jet size down too but haven't had the chance to test it with a new plug yet, should get time to tomorrow ;)