KDXRIDER.NET

Yo! I'm the owner of a 2005 KDX 200 and I love it (been riding for about 5 months). It's all stock but I would like to improve it. I have heard quite a bit about jets, pipes, carb mod and all the likes, and I got to say I don't even know where to start. I'm looking at an easy and inexpensive way (at least for now) to squeeze a bit more performance out of the beast . I have heard something about drilling holes in the air box lid (even removing the lid and covering with pantyhose) but how many and what size (the holes, not the pantyhose )? Do I have to change my mix ratio? I really don't want to kill the engine so any suggestion would be greatly appreciated.

Thanks

Wilf

Great website, keep it up

Welcome Wilf!

All this is pretty subjective stuff...everyone has differing opinions on the order to do them in etc...

But, get it jetted first if you are going to wait a while in between mods. If you are going to add a pipe which is suggested, then get the pipe and jet at the same time. Holes in the air box lid are a good idea for airflow because your bike needs it, but get some of those plugs with the little filters in them (wish I would have done that) it helps keep dirt out and air in.

You fuel ration is a matter of taste. But pick a ration and stick to it. This makes jetting much easier when you add mods. Anything you can keep consistant helps when tuning.

NEXT!

Welcome to the group.

Most people modify the airbox. The main idea is to let in more air, so if you can do that while keeping out the dirt (panty hose or what sounds even better - the filtered air vents, Uni brand I think), then that is the way to go.

Even if you do NOTHING to try to get it to make more power, I recommend that you get the bike properly jetted. I seriously doubt it is jetted properly right now with the factory jetting, so you may want to look into that first, or right after doing the airbox lid modification. Getting it jetted propery is just proper maintenance. If it gives it more power (it will), then so be it.

But seriously, learning how to properly jet the bike is an important skill. You should learn that even if you are not interested in more power. Changes in altitude, humiity level and temperature can all affect the jetting, and I suggest you learn how to jet to deal with those changes. Too lean = engine damage and too rich = build up of carbon inside the engine, especially on the power valves, which if not properly maintained, can lead to engine damage from them being gunked up (sorry to get technical).

If you are looking for inexpensive, then jetting is your answer. If you get a pipe, you will probably need to change the jetting. If you get your carb modified, you will probably need to change the jetting. You may as well ago ahead and learn this important maintenance technique now.

Welcome to the site!

Toss the airbox lid and get some jets to lean the bike out a bit. Unless your 500ft below sea level your most likely on the rich side with the stock jetting. Start shopping for replacement springs for the front forks. The KDX is horribly unbalanced in stock form. The front is sprung for a rider who is 130lbs and the rear for a rider who is 180lbs. Increasing the spring rate on the front of the bike will balance out the bike and make the front end track better. You can pick up used XR400 springs which fit the front end for $20 on a regular basis.

-Maurice

He just wants power, not speed. Hush up about non-engine related things.

thanks guys
I am gonna make some holes in my lid to begin with and put some "home made" filtered air vents. Any website I should look at for the jetting? I am not sure I know exactly what it involves and how to properly do it.

May the KDX force be with y'all

wilf

(sorry, but it is a long standing joke around here)

Drum roll please.............................................................

Do you have the service manual for your bike?

Don't ya mean BIBLE !!!

Might I suggest reading the posts in the Jetting Forum?

http://www.kdxrider.net/forums/viewforum.php?f=105

There is a jetting guide and a several other good posts on various jetting subjects.

Hey I'll take any advice to improve the little green beast!

Service manual? yeah, think so...should I read it?

If your keen, sure, why not. I have only read the bits I have needed. I read the topend section when I did my topend etc. I'm sure you get the idea. Well actually there is a good bit of info through out the whole manual so it can't hurt. Keep in mind it isn't necessary to read the whole book cover to cover even though I'm sure there is a few guys on here that have.

GREAT! Look through there to familiarize yourself with the carb, then check to see which jets are in your carb. YES, they SHOULD be what it says in the manual, but you will never know until you look at them yourself. Buy a few different mains and pilots, then start making one change at a time. That should get you started.

I know may of you guys have drilled holes in your air box but does it make that much difference with the stock pipe? I removed my snorkel and removed the lid to compare and i noticed very little difference if at all. There was a significant difference removing the snorkel but all I noticed was the noise difference when removing the lid, much louder. fortunately I received my FMF Pipe and silencer yesterday and will be installing it tonight, might have to open the airbox a little now.

Did you adjust the jetting any after removing the airbox, eh? eh? eh?

Jetting eh? what's that . I have held off until I got the pipe, it is running a little rich everywhere.

ok , I just removed the snorkel and added 6 holes (1" diameter covered with some foam to keep dirt out).
Let's see what happen 2morrow on the trail. I'll try to jet it as right as a rookie can. Hopefully I won't completly screw it up.
Wish me luck

Take an extra plug or two with you and you'll be set. If you foul a plug don't let it ruin your day, swap it out and your good to go. Keep after the jetting though. Its a neat thing to have a bike that runs well and goes like hell. Kinda like getting your cake and eating it too.

Hey y'all!
I changed the plug after the engine break in and it only has about 15 hours. It is really "neat" greasy black.
What is the problem there? Mix too rich? (I use the recommended 1/32 ratio with motul 100% syntetic oil) or is it the jetting completly wrong?
I will put a new one before I ride 2morrow since I modified the air box and keep an extra one... don't wanna be stuck in the middle of nowhere!

Yep... just running rich. Don't ever jet by mix ratio... stick to what you have.
Do you have any leaner jets to work with? This time of year I wouldn't go too lean, maybe drop it one size but no more.
Make sure you are running a 8 range plug and not a 9.