OK Need some advice

[MADisher]

I have a fairly decked out 98 KDX 200, FMF Fatty Pipe; Silencer, RAD Valve, etc. Maybe 500 miles on the most recent top end. Here's my dilemma.

I've recently posted questions about a 240 upgrade, because I need more power. :D

Scratch that, I havn't heard enough good things to justify even that cost. My KDX is a tractor as it is. 1st/2nd gear I can stand the thing straight up with just a crack of the throttle, past 2nd though, I have nothing, no balls. I couldn't get a wheelie in 3rd if my life depended on it. From 3rd on 250's just up and leave me. I don't mean walk away, I mean leave me like I was standing.

I've read in this forum before that a properly tuned and ready 200 could hang with most 250's. Yet in real life I've not seen or experienced that with mine or two others. Is it a myth ? Do I have a power-valve problem ? I don't mind or expect my 200 to be a 250. But I'm looking for something closer. I spent the first part of today on my bike, the last half on a 2000 YZ250 that was super sweet both suspension wise and power wise. It's been set up for the woods, flywheel weight and all, and I could lug it all day and did.

This bike was sweet at speed (3rd-4th-5th) where as my KDX is down right scarry to ride. I have little confidence in the front end but that's a seperate issue.

I believe my bike to be jettet correctly. I've not fouled a plug in forever, it doesn't smoke, and I have all the grunt I need and or want.

What can I do besides give in to the dark side and buy that YZ ? Will I ever be happy on my Kawi again ? :/ I also rode a new SX400 what a sweet, sweet machine, light, mucho power and thin, man it felt like I could toss it around like a 125 :D decisions, decisions.

Does the power loss (or lack thereof) in 3rd gear on up indicate a power valve problem ? Or just an undersized bike ?

P.S. I don't think it's gearing, I'm using what's recommended on the Just KDX site 13/51? I forget off the top of my head.

-MD

 

[jaguar]

I'd suggest play with different main jets to see if it's jetted wrong (probably too lean).

 

[krazyk]

the havent fouled a plug in forever scares me, I.E. did you check your jeting and correct for the summer weather, and how old is you plug?
If you dont have a set of jets to play with the jetting try moveing the needel clip down to richen the mid raange and that should give you a little more punch in the higher gears.
If you want to run with race bikes that are setup for speed then you might also think of going to a smaller rear gear.
Play with your bike see how it reacts to changes, but keep notes! then you can look back and set it for what you want.
enjoy the time spent playing with it and you will know it inside and out in no-time.
IMO.

 

[Fred T]

How fresh is the top end? Have you done a compression check? A top end tear down might cost a little but will close that door and then you can either fix it or know that she's giving you all she has. Sounds to me like with that gearing you are a little shy on compression. 13/51 should pull the front end up all the way through 4th and maybe 5th too! A fresh piston / rings or just rings might bring her back to life.
Good luck!

 

[Spencer]

I'll say what no one else wants to. A KDX will not run with a 250 (Motocrosser) that has had equivalant mods if we are purely talking about the power like in a drag race situation. It takes some work to make it run with a stocker. Your giving up 50cc and a engine tuned for an entirely different purpose. It will however most definately run with or plainly smoke most of the 250 four strokes built for the same purpose. Note: The new breed of four stroke motocrossers (YZ250F) is a different story. The KDX isn't built to be blazing fast, it's built to be rideable, and it is that. I doubt that your experiencing an engine problem, I have a 2002 KDX200 with mods similiar to your and I run a motocross now and then just for kicks. I'll tell you straight out, A KDX can BEAT a new 250 motocrosser. But it isn't because of the power. The rider better be working his butt off. In the woods, my 200 has all the power I need, It has no problem with hills and goes faster than I can dodge trees. I rode a number of KTM's before deciding on the KDX and found I was getting tired in about half the time due to the power delivery. Don't get me wrong, the KTM is an awesome bike, but I like to play too and you gotta play awfully hard on a KTM to have fun versus the KDX.

 

[Bread]

Spencer is right. You have to step back and look at what you are talking about. The KDX is an enduro bike, meant for the woods, the KX's CR's ect are track bikes, sure people ride em in the woods, desert, GNCC and such, but they are a totally different monster. Let me start over and say that I'll probably get some flames for this post but its just my opinion ok. If you drag race a KDX and a KX for a mile or so, who do you think is gonna win? Me, I think the KX will every time, its just the way they are built. You start riding trails and such then you have a lot of factors that is going to bring the pace down and make the two bikes run alot more closely. I've not got a lot of money to pop into a bike to make it a killer machine. I've put a pipe and can on it and thats about it, and I've come to live with the fact that I'm not going to be able to make my front end come up with just a twist of the throttle in 4th gear. I have to plan ahead, and sure it takes some effort to get the front end up in a higher gear. Since I've added the pipe I dont think my jetting is 100% either, still runs a little rich, I've just not taken the time to fine tune the bugs out but thats the way I am. When I used to ride I would just lug the bike in a fast trail in a higher gear, now I ride it more to what I would think I would ride a 125, I keep it a gear lower and keep it in the pipe. I never ever used to do that, but I think now I ride a little faster because of it. The KDX is a dependable rock solid workhorse. You point it at a hill and tell it to go and hang on for the ride. Crack the throttle and you can go just as fast as any other bike on a tight trail, but the fact is if you want to race on a mx track or gravel roads your gonna find yourself lacking. I've ridden a KX500 several times, it has great hill climbing ability and super super scary speeds, but honestly truthfully I'm scared to ride it. I feel comfortable on my KDX, and everyone that I've talked to that has owned one all say the same thing. The KDX is the most rider friendly 2 stroke they have ever been on. Its just an all around good bike, if you go around trying to make her something she is'nt your not gonna be 100% happy.

Like I said before, thats just my opinion.....be gentle with me
PS. As i was saying about rock solid, until I changed pipes and started screwing around with the jetting I had never ever in 4 years on a KDX fouled a plug and its my fault that its done it now

 

[MADisher]

I started off saying that I know it's not a 250 or a race bike. :)

Never foul a plug but I still change them regularly and they look fabulous ;D (Yes, I change the oil, clean the air filter too). The Top end I would guess has about 500 miles on it give our take, it was done spring of last year. I don't suspect jetting, because of the fine condition of the plug when I change it. That killer coffee color (or a tad black if I lugged the hell out of it from my last ride behind a child).

What my KDX feels like is is a 125 with torque and it has torque. It is still the bike I would choose for a play bike and have no regrets what-so-ever in buying it.

I know I need some suspension work, my forks still suck, and we all know the KDX isn't the greatest jumper especialy with a 220# rider.

Perhaps my biggest problem is what I'm comparing it to. Set up 250's or 426's or KTM's with killer suspension. Believe me you couldn't pay me to ride my fathers Squisshy 'love-boat' DR 350. But, I would think in a drag (1/4 mile or less) I should get a good start vs that basically stock DR, and they he'd get me in the taller gears. I can't get away from him no matter how hard I beat it.

like I said I have power in 1st-2nd, but little to nothing in 3rd. I can't blip the throttle or twith the throttle in 3rd to get over something like a hole or a log, which I can easily do a 250. I still subscribe to the throttle will get you out of a lot of trouble, yet I since I don't have it in 3rd/4th I'm a lot slower on fire roads and things of that nature.

Maybe I will double check the gearing and play with that. Maybe it's geared lower than I think.

-MD

 

[Robcolo]

Madisher, IN a straight line my reworked 220 will keep up with the "average" 250MXer & even pull away top end because of the wide ratio gearbox [unless he's geared really high] BUT --BUT as you said in your original post, you can't trust the front end - and neither can I. As soon as that straight turns right, left, up or down I'm way off of the pace as the KDX is just not capable of safely going fast. I.ve had the shock revalved & resprung and installed springs and Gold Valves up front with noticeable improvement, but my old KX is still much easier to ride at speed. I'm convinced that the front end washout problem is due to too rapid rebound. Unfortunately Gold Valves don't affect rebound. Somebody offers a $125 adjustable rebound valve but I hate to have spent more on the suspension than in buying the bike in the first place! Anyone know how to slow that rebound ?? 10W fluid??

 

[canyncarvr]

mad:
You'll get more spit and better pull with an RB 36mm carb.

A DeltaForceII reed cage is a large improvement over the radvalve.

...but you've heard all that before! Time to get out the 'ol plastic and get on the web!!

 

[MADisher]

Yep Canyn... Before I put $1000 bucks in this this thing I'll sell it and put that $1k towards a pumpkin or that YZ I rode :D I'm just not convinced I'll get what I'm looking for even for $1000 and I'd still be afraid of the front end :/

-MD