KDXRIDER.NET

Finally had a chance to ride this 2006 that I bought for my son. I guess the bottom and mid power are OK, but it seems to not have much over rev and doesn't pull very hard on top.

When idling the engine is noisy as crap hammering like a mason jar full of marbles (very loud), bring the rpm up gradually with the throttle and at a certain rpm the noise goes away like you flipped a switch. So I assume that the power valves are moving ok?

For some reason, and maybe it is my imagination, but it seems like the noise isn't quite as loud once the bike is fully warmed up, still present, just not as loud, and will quit making noise at the same rpm. Does that sound normal to you guys?

Motosport still has not sent my main jets. That being said it still has a 160 main, would this cause it to not pull up top? It is not really cutting out or anything, just not over revving and pulling like I would have expected it would. I have installed a 45 pilot and leaned the stock needle one clip. In the low and mid range it doesn't feel too bad, no power house but I am used to my son's 103 super mini and my 250 KTM so it is hard to judge.

The bike is stock, has good compression, gnarly woods pipe and Turbine core 2 silencer. Removed the air box lid and noticed only a marginal improvement, but it made way more noise! BTW I cleaned and repacked the silencer and installed two new plugs.

So am I just expecting too much or what?

So far I am very un-impressed with this KDX. I feel my son is going to be very disappointed climbing off of his super mini and getting on this under powered trail bike.

160 main jet is way to rich for sure. Also the Woods pipe won't do th top end power any favors but the biggest thing you could do to it is re-jet.

I bet that pipe is completely full of gooey spoo...

My 200 runs like a strip'ed assed ape!

That bike need maintenence is all....

The noise you are hearing is the KIPS and is very normal, almost
sounds like it's ready to come unglued till you hit about 6k and then
disappears.
The woods pipe will give you more on the low end and the desert
pipe more on the top end.
If you want more on the top end you might find someone on this
site willing to trade your woods for a desert pipe.
Spend the time to jet your bike properly and you will not be disappointed.
When set up properly they are by no means underpowered.
Good luck

I understand jetting, and I have ordered jets they just haven't arrived yet.

I am just trying to find out how these things normally run, it is hard compare this KDX to my KTM or my son's super mini. That super mini is a little monster with a pretty good mid range hit.

A friend just told me a half hour ago that these bikes are not renown for lots of top end power. He stated that they are more of a low to mid engine in stock form, and he has been around these bikes for several years. He stated that I am just used to my 250 KTM with a modded head, and he is probably right.


BTW I have cleaned the pipe out, cleaned and packed the silencer, fresh air filter, fresh fuel, fresh plug, Fresh tranny oil, fresh (engine ice) coolant, just bled the front and rear brakes, lubed the neck bearings, lubed the swing arm and every single piece on the rear suspension including front and rear axles. Trued the front wheel, laced up and trued a new rear wheel. New plastics, new graphics, new levers (clutch and front brake), new Bridgestone tires (404 & 403), new Pro Taper bars, new Moose contour bark busters, etc..

In the last three weeks since I bought this bike I have taken it apart and maintenanced everything but the top end & it seems to have excellent compression so I haven't touched it yet. I am doing everything that I can think of to make this a nice bike for my son (safe, good running and nice looking). I didn't want to spend $8000 for a new KTM 200 that I couldn't easily lower the suspension on, so that is why I went hunting for a late model KDX; that and I have always heard good things about the KDX's.

Unfortunately I had never ridden a KDX before.

To expect the KDX to run like your KTM 250 is quite a stretch. I know how these can run since mine has more everything than what I could ever use. I have DF3 Reed cage, RB head and carb, 100 watt coil, no lid on the air cleaner, FMF Woods pipe with a FMF Turbine Core silencer.... I think that's about it for running feel.... My jetting is at 150, 42 I believe with a JD RED needle.

If my bike wouldn't impress you... no KDX would. My brother said it is twitchy... If I remember right... My KTM 250 EXC was twitchy too.

Indawoods wrote:To expect the KDX to run like your KTM 250 is quite a stretch. I know how these can run since mine has more everything than what I could ever use. I have DF3 Reed cage, RB head and carb, 100 watt coil, no lid on the air cleaner, FMF Woods pipe with a FMF Turbine Core silencer.... I think that's about it for running feel.... My jetting is at 150, 42 I believe with a JD RED needle.

If my bike wouldn't impress you... no KDX would. My brother said it is twitchy... If I remember right... My KTM 250 EXC was twitchy too.

Does the RB head and carb mod stretch the power band out some, or do you have to raise the ports to widen out the power band towards the top end?

What does RB charge for the carb and head mods together?

A 200 doesn't need anything more up top. I don't know what is wrong with yours... I suspect something with the KIPS. Mine climbs to the moon...

Just because the flap is rattling doesn't mean the KIPS is timed right in the jug. If I were you, I would just go ahead and do the topend to check the KIPS. This is more common than you think. Ther was just a member who had this issue with his new purchase. The valves were not set right and the timing was off.

You can check out http://rb-designs.com to get his pricing on the head and carb mods.

Where can I find the information on the proper timing of the valves?
Or is this pretty self explanatory once you get in there?

I really feel that the bottom end and mid range are pretty decent just rolling on the throttle and not whacking the clutch, it is just that the power band seems a little narrow and not much pull up top.

The previous owner bought the bike new and never touched it, no jetting or nothing, only bolted on a pipe and silencer. He was a pretty tame rider (dad following his kids around) and didn't really put too many hours on it either. Main thing was that he didn't know how to perform much maintenance. I haven't really found anything that looked bad other than the silencer was pretty gooed up due to the overly rich jetting.

It is in my nature to perform in depth maintenance and check things out, so that is what I have done.

Can the KIPS still rattle if the side valves were stuck?

Boy I sure wish we lived closer to each other, I would love to have you ride this bike and give me your opinion Indawoods!

Yes the KIPS will still ratlle if the side valves are stuck. My bike had the left side valve stuck and after fixing it the gain in top end power was really big.

timing of the valve is self explanatory once it's opened up.
however the manual has it WRONG when they tell you the left has a groove . You'll see if you put them in as the manual states, something doesn't line up.

Great thanks so much for the info fellas.