why such a dog

[James51381]

i took it in to service, to see if it needed a new top end. the guy said that it had a really good compresion. he rode it around and said it isnt running half of what it should be. granted it has the stock jetting, but I really didnt notice much of a power difference. I did notice the 49 tooth rear sprocket difference. He also took of the timing cover and discovered a reall small leak, but said its not big deal yet. my power valve is working great, so he said the only thing left is the carb (stock mind you) so i was thinking to send it in to rb designs. could this fix my problem? i have no mid or upper power. after the first initial "punch" there is nothing. any suggestions? thanks
James

pro circuit pipe
v-force cage and valves
fmf arrestor
no air box lid
49 tooth rear sproket

 

[BRush]

You said you took it to a mechanic for a compression test. Did he happen to do a leakdown test or check the timing, while he was in there?

Some quick hits:

Take the carb apart and clean it.
Jetting - Read this article and use the recommended jetting as a starting point:
http://justkdx.dirtrider.net/carbtuning.html

Carb - float level checked?
Carb vent lines unblocked?
Gas cap vent unblocked?
Silencer - repack it.
Premix is fresh?
Air filter ok? Not excessively dirty or over-oiled?

Good luck.

 

[CaptainObvious]

When you say your carb is stock, does that include the jetting? If so, I'd change the jetting prior to sending it out for an overhaul.

You also mention that the powervalves are working. How do you know? Take the cover off the side of the cylinder and run the throttle up and down. Make sure the rod moves up and down as you reach the higher rpms. After you confirm that the rod moves, remove your pipe and manually run the rod (with the engine off) to confirm that the powervalve drums are actually rotating.

 

[smb_racing]

Originally posted by James51381
He also took of the timing cover and discovered a reall small leak, but said its not big deal yet.

what kind of leak? a crank seal leak? if he says a leaking crank seal, even if it is slight, isn't a big deal it's time to find a new mechanic.

 

[James51381]

yes the jetting is stock. when i send the carb out to get mods, they will jet the bike according to my mods. the leek is by the timing thing......... i am knew to bikes, so he said that he took of the cover and discovered it. i will check the hoses, filter is clean, where can i find the power valve i am supposed to check? the mechanic is good, he has worked on my dads street bike before.
are there any of you guys out by Fremont California, that would help me out?
thanks
james

 

[CaptainObvious]

STOP!!! Don't send the carb out yet!

First off, what year KDX do you have? What is its overall condition and service history?

Secondly, on their own static compression tests don't tell much of a story. They are mostly unreliable and are only a useful tool used when evaluating the condition of the top end with other factors. Personally, I like a differential compression test (also known as a leak-down test).

Lets look at the problem in steps.

<< after the first initial "punch" there is nothing >>

This “could be” a powervalve malfunction. See my post above for trouble shooting the PV. The PV cover has the word KIPS on it.

It could also be your jetting. Symptoms of rich jetting are burbling at mid throttle, hesitation at full throttle, a wet spark plug and excessive smoke. Rich jetting could also cause the powervalve system to get caked with carbon, leading to its failure (the gears strip). So if your jetting is rich there is a chance that the PV system is malfunctioning.

<<took of the timing cover and discovered a real small leak, but said its not big deal yet>>

Ahh, when will it be a big deal…when you cease the engine. Take care of small problems BEFORE they become large ones.

Before you can adjust your jetting you will need to determine whether all of the other systems on the bike are working correctly. Have the small leaks fixed. Make sure there are no leaks in the intake and exhaust system. Clean your carburetor and check your fuel line and petcock for clogs. Make sure your ignition is making proper spark.

When you do adjust your jetting use the recommendations on the dirtrider.net/justkdx website as a starting point. Most important (engineering rule here), only change one thing at a time. If you do to many things at once you will not be able to determine which item(s) had a positive or negative effect.

 

[Jim Crenca]

I'd have to agree with all the above.
I have done all the usual mods, and while they all collectively make significant improvement, the bike did not have engineering problems that would keep it from running like a decent 200cc trailbike. If "the guy" said it wasn't running half of whait it should be and didn't fix it then he wasn't a mechanic. It probably is in the jetting assuming all other systems are OK. Find a new mechanic, find a pal who knows 2-strokes, or get a book (Eric Gore's tuning book is easy to read and very good IMO).

 

[James51381]

its a 97 kdx 220, with no mods at all to the carb. the maintanece history is none, he have had it since new. we did all the of oils and plugs but that is it. it was never really used untill about a year ago. so it is still in good shape. i will try to inspect the pv
thanks
james

 

[nectar]

Repack the silencer....then see how it runs.

 

[Matt90GT]

How many turns out is the air screw?

When I got my 250 it just died and sputtered past half throttle. adjusted the screw out about 2 turns from the 1/2 it was and there was the missing power. Takes 2 seconds to check.

 

[James51381]

dont know about the screw. but i will check. thanks alot.
the silencer is new, so no need for packing.
thanks guys.

 

[Michelle]

James, if I were you, before going any further, I'd rip the old piston & rings out & chuck them & insert a Wiseco kit.
You say the service history is none. It's a 97 220. Stock 220 pistons have been known to grenade (if you do a search, you'll find more on this). I really wouldn't be keen on riding the bike unless I'd done the top end, no matter what the compression test & mechanic say. It's cheaper to do than to repair the damage done if it does break.
That's just my 02c
Michelle

 

[James51381]

so a top end rebuild it is. can i do this at home? how about the new piston. i have worked on cars before, so i know to use the screwdriver with the sockets. :) have any of you heard about the seal going bad on the side of the ignition?

 

[Michelle]

Top end can be done at home. Check out the "All KDX riders should read this" thread. Under tech tips I'm sure there's a top-end rebuild article.
On Fredette's video there is a piece about a leak on the ignition side of things - it can be the cases that is leaking, not the seal. The flywheel will need to be removed - you'll see three? grooves & the aluminium plating may not be complete, so you'll need to epoxy the holes.
Before you get into the top end, ensure you have a manual - makes life easier ;)

 

[Canadian Dave]

It sounds like your top end hasn't been rebuilt since the bike was new so the piston is on its 6th season by now. I'd recommend you service the top end and replace the stock 220 piston with a Wiseco piston. The stock 220 pistons have a reputation for cracking particularly if the engine has been modified as your has. While you have the top end off you'll want to clean up the power valves as well and ensure they are operating properly. Before you start be sure to pick up a Kawasaki shop manual and have a look on the JustKDX web page for top end rebuild tips. These include things like the proper disassembly of the KIPS system to avoid damaging the main shaft as well as a correction to the manual ( the left and right kips valves are wrongly identified)

As for the weeping crank seal, be sure to watch it carefully. If you have an experienced mechanic that is telling you it's a point of concern but doesn't need to be addressed quite yet then its likely just a little wet around the seal. If the seal starts to leak, air will be drawn into the crankcase leaning your jetting (lean = more air in the flue/air mixture than what is ideal). This can result in damage to the engine internals. Things like the piston, connecting rod bearings etc can overheat causing considerable damage. The unfortunate thing is the KDX's crank seals can't be replaced without splitting the crankcases making the repair a little spendy. If you find you need to split the cases to replace the seals consider rebuilding the bottom end while you're at it. The labor involved in splitting the cases to get at the seals is often the majority of the expense so you may as well go over the reset of the bottom end while you're in there.

In addition to the things already mentioned check the operation of your CDI and ensure its working properly. It could be one circuit is burnt out and the ignition map is no longer being followed correctly. The Kawasaki shop manual includes test instructions for the CDI. The chances are slim this is the problem but its worth checking. If you know someone with a 1995 to 2003 KDX200/220 ask if you can give their CDI a try in your bike and see if it works any better. Don't go out a buy a CDI to see if it fixes the problem until you're certain it’s the cause. They are expensive and don't often go bad.

Lastly have you ridden other KDXs? It could be your mechanic is accustom to 250CC MX bikes and is unfamiliar with the KDXs power delivery. It could be everything is just fine and he's just not KDX liberate?

Good luck and let us know how things are progressing along.

David

 

[James51381]

thanks for all the good info. the mechanic has worked on kdx's before. I guess I will redo the top end and piston. i had a 91 kdx 200 and that is faster than mine. i havent really gotten a chance to ride the bike with any mods, since i did them all at once. it is true its is 6th riding season. but if you put in the hours it has ran, its probable on it's 3rd. How will i know if i have to crack the block in half? and can i do it or does a mechanic have to do it?
Does anyone around Newark CA have a bike similar to mine that can ride mine or let me ride there's so i have something to base my bike on?
thanks alot
james

 

[canyncarvr]

RE: "The PV cover has the word KIPS on it."

What's under the cover with the word KIPS on it is a hole. It's the helmholtz resonator. No power valve workings will be found there.

On an 'H' model kdx you can find the end of the main KIPS shaft (and a nut to turn it with) under the slotted cover on the LH side of the cylinder. With the pipe off you can turn the nut while looking into the exhaust port to see if the main valve and the subport drums are turning as they should...in sync and to the right positions. The service manual has a good explanation of the KIPS operation. You need to get the manual.

You have quite a few things to do before sending the carb off somewhere. Is the fuel fresh? Air filter clean?

And, as CD said...what you describe could well be a perfectly running kdx compared to a kx. Just because this mechanic has worked on one before doesn't really answer the question CD asked...is he familiar with the power delivery of the kdx? I'd be wary of a mechanic that said 'it's not running 1/2 of what it should' that didn't adjust the air screw himself.

 

[Barker]

My girlfriend just purchased an 03 220. I've had it out in the hills a few times in the desert. The power is kind of deceiving. First time out, wow, what a dog was my first impression. Second time out it was worked on tight, singleline, switchback, steep uphill paths. Best way to describe it is like riding a roller coaster on the up part of the track when the chain is pulling you. Very steady, tractable power deliverly. Everything gets put to the ground. We meet another KDX rider on a modified late 90's 200. Got to try that out a bit, it was perky, but no where near a 125 MX bike. It felt faster than the 220, but getting right back on the 220 (she does get to ride it!) was a more pleasent, effortless ride. So far the only mods have been to remove the airbox cover, relocate the ign module, and put on a 4.4kg rear spring (shes 125lbs). The bike is on the rich side, but being a new bike, it will take a while before she lets me wrench on it that way. I'm new to this board, will take a look at other post to see which way to go with the carb and pipe stuff. She has been on a 00 KX 100 for the last three years, and is having trouble getting use to the height of the 220. Need to check how far the front forks can be dropped, and look into longer pull rods.
Mike

 

[canyncarvr]

Devol pull rods are real pretty. Lower the rear about 3/8". Kouba makes three different sets that take you down as far as 2+ inches.

 

[Barker]

Dropped the seat off at lunch. $40.00 to shave it down, put a protective liner over the shaved foam, and modify the seat cover. We'll start here.
Mike

 

[Razorback]

"Best way to describe it is like riding a roller coaster on the up part of the track when the chain is pulling you. Very steady, tractable power deliverly."

I have 3 bikes (02 KX250,02 XR400,01 KDX220)
Each bike has it's strengths and it's fun factor.The KDX is a bike that I can take to the track,desert,or mountains and have a good time and run with any crowd.The power does get to the ground and the engine just keeps pulling with a 4 stroke attitude.The excellant handling make it a dream in the hills and tight nasty trails and it's much lighter than my XR.The XR can climb damn near anything but it can be a real handful going down steep hills.The KDX is very easy to navigate down hills and the 2 stroke snap is a dream when you need to loft the front wheel.The six speed gearbox and soft suspension hold it back on the track but not enough to keep it from being fun and competitive with any novice to intermediate rider.I can't think of any other bike in it's price range that I can do as much with.I'm a B level rider at 5'11" and 210lbs.My 220 gets me around quite nicely.Last Saturday I went to El Mirage with my friends and the bikes were an XR600,KTM500,CRF450 and a new YZ450.Me and my little 220 led the pack for most of a 54 mile ride.l fell behind in the middle of the loop when we hit the flat open desert but only because I'm to afraid to ride sixth gear wide open.One rock or rut in the wrong place and it's all over.I know the other bikes are faster in the open but I don't get blown away like many may think.Because the KDX power does not feel overwhelming it is often an underated bike.On the flipside it gives the rider a great deal of confidence,less fatigue,and a great deal of fun.This is my third KDX and all have been trouble free.I've spent money on tires and maintenance and a few mods but not a dime on breakdowns.

 

[James51381]

adjusted the screw under the idle screw. and it helped a quite a bit. i have some low end and then none at mid, then the top end it pulled hard. is there anything else i can adjust to the carb. it is the 33mm, but with the recommended jetting from justkdx.
thanks for all the help
james

 

[cr25096er]

the needle jet. it sounds lean if it just revs n dosnt make much power. if it blubers its rich.

 

[James51381]

i did the recommended stuff on justkdx for the carb. Can i move the clip on the needle to the very top? i have no mid range power. should i move the needle up or down a notch.
thanks
james

 

[CaptainObvious]

Depends, are you running rich or lean. Most KDX's run rich from the factory. With that in mind move the clip up one notch to lean the midrange. Make sure to check your plug after making the move.