KDXRIDER.NET

Hello all, I know that some of you have or know about the KDX 125, well mine is a 1991 or 1992 model and I think I had a lean seize on it and now I need to replace the piston as well as a bunch of other things on it. My issue where I need some help is figuring out what piston to use. Because of the lack of 125s in the US, I can't find the exact one on ebay although I can find a bunch of KX125 pistons. Current piston was not original and I don't have info on it. So my question is, what would you recommend that I use?
As a side note, is there some way to tell for sure what year this bike is?

Thanks!!

Check the Kawasaki parts database and look at cross utilization of that piston. Might be the same as a KX 125.

This is probably a stupid question, but where is the Kawasaki parts database? If you're referring to Kawasaki.com/Owners... that only includes US models which the KDX125 was not part of.

I would try contacting the various piston manufacturers and see what they say. I'm sure at least one of them made pistons for it at one time.

Here ya go!!!

http://wossneronline.com/forged_pistons ... cts_id=495

Awesome thanks for finding that, but WOW that's more than I can spend on the piston. With international shipping to me I'd be looking around $150!! Too much for a 20 yr old bike that is worth $750, at least that's what my wife is going to say.
That's why I've been looking at KX pistons, I'm just not sure it'll fit/work correctly. Like the skirt, ring gap and stuff.
What do you guys think? Any other 125s out there? I can't be the first to try this.

I've been comparing numbers on these diagrams and it looks like the only difference is that the KX only uses one piston ring versus the KDX 2 rings. The connecting rod and pin are the same.

http://www.cmsnl.com/kawasaki-1991-a2-k ... E1320.html

http://www.cmsnl.com/kawasaki-1991-h2-k ... 1320A.html

What's the difference with using a piston with just one ring?

I wouldn't say the pistons are "the same" because they look that way on the fiche. Look on ebay for a Wossner piston.

Mfkdx wrote:I've been comparing numbers on these diagrams and it looks like the only difference is that the KX only uses one piston ring versus the KDX 2 rings. The connecting rod and pin are the same.

http://www.cmsnl.com/kawasaki-1991-a2-k ... E1320.html

http://www.cmsnl.com/kawasaki-1991-h2-k ... 1320A.html

What's the difference with using a piston with just one ring?

They used 1 ring on the kx for faster revving. They also wear faster with just 1 ring....but like slick nick said, don't assume they're the same by looking at a picture. Exact diameter, height, piston skirt shape, wrist pin bearing size, oil holes, etc. all need to be factored in.

OK, cool I guess I'll try to get one and compare it to the pics of what should be in mine.

Thanks

Even though they use the same wrist pin it might be located farther from the crown or closer to the crown. In either of those situations you might have a serious problem, even though it appears to fit otherwise.

Save yourself the headache, and just pony up and get the Wossner. Even if the KX dome height is off by a few thousandths of an inch, you'd be looking at a new engine if you tried to run it.

Here ya go. No reason to even think about a KX125 piston. 32.95 pounds or $52.61 U.S. Visit this Ebay store and search "KDX125 piston": http://stores.ebay.com/D-G-COMP-SHOP?_t ... 4340.l2563

Really! A few thousands of an inch and kaboom?!? I can compare the crown height with the current one before installing.

Noone in Europe has tried this? It should rev faster with the single ring.

Mfkdx wrote:Really! A few thousands of an inch and kaboom?!?

Yes, really, if it creates any interference.