KDXRIDER.NET

I noticed on a post in the newby section that the 220 pistons like to break. So whats up with that? I figure that if it happens that much, Kawasaki would surley address the problem because pistons should not fly apart on a new bike. Is there certain situations where this happens? I'm going to change my piston eventualy, but I'd like to ride my bike with alittle confidence that it's not going to go down on me when I need it most. So whats up with these pistons? Why does'nt the 200's have the same problem?

Jon.

Jon -
I don't think anyone knows why they come apart. They just do... it might be a year from now, it might be 3 days from now... no one knows when... but it most likely will. If it's past your warranty period and you didn't follow the Kawasaki procedure for breakin. Then Kawasaki sees it as your fault. During breakin, Kawasaki wants you to tear the top end down and inspect it. Who does that? No one I know of.
Do not replace your 220 piston with a Pro-X or else your just putting in what came out of it. Go with Weisco and you shouldn't have any problems with it.

As far as the 200's goes... same thing... who knows. They just DO hold up. And a Pro-X is what I am rebuilding my topend with right now.

I was going to go with a Weisco piston set when the time comes. I've never heard of Pro-X. I would think Kawasaki would have at least looked into any problem like that if they were so numerous. Thing that does'nt make sense to me is why would you need to tear down the top end for inspection if there is no problem with your components. Kinda tells me they know about the problem but refuse to agknowledge there is a problem. This sucks! I've never torn down a top end on a new bike like this. How difficult is it?

Jon.

The manual will show you how.... It's easy... do it once and you can do it in your sleep.

"but I'd like to ride my bike with alittle confidence that it's not going to go down on me when I need it most."

You can have a little confidence right now. If you want a lot of confidence, buy a Wiseco piston kit, small end bearing, top end gasket kit and fresh coolant, then swap them out. Sorry to sound like Mr. Spock, but what Kawasaki should or shouldn't do will have little affect on the 69mm potato masher inside your cylinder.

ACHTUNG

Jason wrote:Sorry to sound like Mr. Spock, but what Kawasaki should or shouldn't do will have little affect on the 69mm potato masher inside your cylinder.

ACHTUNG

I know, but it just seems screwy that you would need to replace a piston on a new bike just to have piece of mind that it'll stay together for you. It does'nt say much for thier quality. But you are right Mr. Spock, it has little conciquence on the situation as it is, and it won't keep it from flying apart. So I'm on it, hell whats another $100 or more now? I got it looking half way racy, might as well do a piston replacement.

jon.

OK, done deal. Just ordered the Weisco piston kit, wrist pin bearing and topend gasket kit. Should shore it up. Now just hope it does'nt blow before I get it done.

Jon.

"...hell whats another $100 or more now?" Spoken like a true dirt biker!

You are 100% right that it stinks that Kawasaki has not fixed the problem. I suppose no bike is perfect, but that is a common known problem. I think there have been a whole lot more Wiseco pistons purchased than Kawasaki pistons that broke. I would rather not take a chance if I had one.

If you get time, can you take a couple of pictures of your new Wiseco piston when you get it? My buddy wsjkawasaki bought a 1997 KDX220 about 3.5 weeks ago. It had a Wiseco sticker on the radiator shroud. The country bumpkin he bought it from said the previous owner had a "wi-ZE-ko" piston in it. When we stripped the top end a couple of weekends ago, it didn't look like what I would iamgine an OEM piston to look like, but if I could we could see a picture of a new one, I would be more comfortable. The piston had little carbon build up, while the rest of the bike looked like the guy had wrench-aphobia, so I am figuring it is a Wiseco. I just want to see a new one. :-)

If you don't mind me asking, did you buy a new off the showroom floor 2003 model, or was it a used model? I am sure you said which in an earlier thread, but I can't remember right now.

There is "something" going on with this whole piston and cylinder issue. As we all know, there are pistons in these 220's that have broken. That is a fact. We don't know why for sure though. There is another issue, that is the cylinder plating, or something in the cylinder can cause unusually bad wear. Look at the thread I started "Cylinder is Toast" Here I sit with 8 hours on my engine and a cylinder that is really scratched up bad. Piston is OK, but the cylinder is way to loose. My dealer spoke with Kawi for warranty reasons as this bike is still under warranty. Kawi told him they have never heard of this??? My dealer has seen 2 in the last 3 years. Also, there is a statement in the owners manual to pull the top end off at 2 hours to check for ...something. Why? What other engine have any of you ever heard of that needed to be tore down after break-in to check for possible damage? And another thing, Ron (RB) knows about this because he fixes these probs. FRP knows about it, just about any Kawi shop knows about it. We know about this because we have either had it happen to us or know somebody that has because of these KDX web sites. And here is Kawi telling the dealer that this is strange? I don't like this one bit. I am still waiting on word from Kawi if they are going to replace the cylinder. I will have the ports chamfered as a precaution. I will put in a Wiseco. If I had to do it all over I would have gotten a 200.

When you say 8 hours, do you mean you bought it brand new and put 8 hours on the engine?

When you say the cylinder is too loose, what do you mean? Have you measured (or had measured) the cylinder, piston and rings?

If I ever get a "brand new" anything, I am going to tear it down before I even crank it.

This was brand spankin new right off the show room floor. It had been started around 4 times before I bought it according to the dealer. It has 146 miles. 30 of those were break in miles. The mechanic put the piston in the cylinder and could immediately feel it was too loose. Later he did measurements for the report to Kawi and he told me it was out of specs. We both suspect that because there was nothing showing on the top of the piston (there was not a sign of damage) that something came loose within the cylinder to cause the wear marks. The only thing it could be is plating or pieces of metal around the ports as the marks all align with a port. I would have taken pictures but I took the cylinder in immediately when I saw this. I wonder what would have happened if I would have stuck to my original plan of waiting until after the warranty to tear it apart. It was only because the weather and trails here are too cold and icy to ride that I did it now. It may have gone on fine then this whole mess would be all mine to send to RB. Maybe this is as Kawi says it is, an odd and rare occurrence.

You think it may have had a 200 piston installed?

Dude, your pain pill is working fine. That 's a 3mm piston diameter difference, ya know.

200 is 66mm and 220 is 69mm.

Well... wouldn't that cause a "loose" condition? Hmmmm?

I'll have the actual size numbers tomorrow. And as Ski said in another post :
"Touch the edges of your ports where they meet the cylinder walls with some emery cloth to knock any sharp edges off. This is a source of cylinder scoring if a piece of electro plate flakes off and rattles around in there".
I would like to take the cylinder home to do this if the dealership will allow it on the warranty. Maybe I will have them do it. It will be done one way or another.

What I would like to do is tell them to cram the cylinder and for Kawi to pay for RB to have his way with it. It would be cheaper to them this way.

That would be funny. A 200 piston in a 220? .120"??!! I guess 'Doesn't fit' would apply!

Pro-X is the company that **edit provides edit** the pistions for the KDX.

Why is the 220 bad and the 200 OK? I dunno. It just is.

Why doesn't Kawi fix it?

I'm sure they have that on the list. Right after:

1. BNG for next year's KDX
2. Forks that work
3. Tires that are any good
4. A lighting system that does something
5. A kicker that isn't bogus
6. etc.
7. etc.
and furthermore....
8. etc.

Then maybe they'll fix the 220 piston problem.

ACK! Pro-X doesn't make those pistons. They just sell 'em. Go to pro-x.com for more info.

The most likely culprit is the ART company.

From the Pro-X site:

Prox Racing Parts are mainly manufactured in Japan by reputable Original Equipment Manufacturers.
The latest, state-of-the-art CNC equipment, machines ProX Racing Parts to our exact specifications and high quality standards.

Correct. I meant they supply the pistions for both models.

Thanks for the clarification.

I don't think they supply them, from what their website says. Maybe they get their aftermarket pistons made by the same people that make many OEM Japanese pistons. That is all it sounds like from their website.

Well, to me anyways.

You know, all this brings up alot of questions on why Kawasaki does'nt do alot of things. The piston is just a start, I mean I'd rather pay a few hundered dollars more at the showroom if they would put a better quality piston in thier KDX's not just the 220 model all of them instaed of having to tear this sucker down myself. Next, why the heck don't they just convert the front ends over to inverted forks???? If I'm not mistaken, the KDX is the only bike over 200 cc's thats still running conventional forks. It can't be that hard to redisign the front clamps to accept the newer forks! I'd pay the extra$$ for that too, hell make it an option or something. I don't know of to many enduro bikes that do not run inverted forks, or thier customers replacing pistons on new bike engines so they won't have total engine failure.

Sorry, I'll get off my soap box now, I still love my bike though it's gonna take some work to get it where I want it, guess thats half the fun???? $$$$ I'm a hopeless KDX'r.

Jon.