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I have read on this site that the cylinders on the KDX 200 are stamped for what the original piston size is i.e. A, B, C.....
Where at on the cylinder do they stamp this, I have looked, and I am not seeing it?

I have never seen such a stamp on the cylinder. Pro-x is the only piston you can buy which will have such sizing options anyway. A would be the stock size. B, C, D, are "slightly" oversized to compensate for cylinder wear.

I understand how the oversize system of Pro X works, but thank you for the information my friend.

I had read on this forum that Kawasaki stamped the cylinders as to what size they came out of production at, most likely it would be an "A" or "B".

I looked closer at my cylinder, and on the left hand side I did find a stamp (not casting) that is the letter "A".
If this is true, it looks like mine was an "A" when new. So as good as this cylinder looks, I can only assume it would be safe to use a "B" piston next time.

On the KTM's we normally go to a number 2 piston when we do the first top end. I would think that same practice could apply here as well, since the difference in piston size between an "A" & "B" is so very small.

Thoughts?

Seems like I read somewhere that the marking was on the piston not the cylinder. I think some of the OEM's were B, C, D's as well as the A's. Your talking about a diff of .01mm or .0003 inches. You would have to go from the A to the D to make up one thousandth. I don't think most folks even have tools accurate enough to reliably measure a bore that close. These sizes are used by the OEM to make up for diff. in plating. I would replace with what is currently in there. The piston will probably wear long before the bore, and piston to cylinder tollerance is 8x this difference so I doubt it would matter much.

^^^^^ Exactly.

What I was trying to get across was that I do not think there is any marking on the cylinder. If you read something here that says there is such a marking, I would like to see the thread that you read it in. If you buy a std OEM piston, you will get the equivalent of a pro-x B piston AFAIK. You do not have an option to match the piston to any marking on the cylinder.

Hi in the UK we can get the Wossner Racing Piston they come in three sizes.

I very well understand the sizing of the Pro-X pistons. I was simply stating that I had read on this site that the factory stamped the cylinders when new as to what size they were A,B,C etc......... I have been rebuilding engines since the 70's, I do understand how oversize pistons are sized and how they should be used.

And yes, I did read on this site that they stamped the cylinders, but I went through like fifty pages that day, and now I can not find the thread. I am not going to read through all of those threads again.

If I keep the bike I will take a bore gauge and measure the cylinder. I was only asking where the said marking was located. For the record I did not find such a stamp or mark. What I had seen was in fact a casting not a stamp and it was a number 4, not an A

I was also making the point that it is such a small difference in size between an "A" & "B", that if my cylinder was in fact an "A", I could easily use a "B" piston with no ill effects.

Bottom line I don't really know if we are going to keep this bike anyway, my son thinks it is a complete dog compared to his KX 103 mini, and I have to agree. I have had two different friends that have been KDX owners ride this bike, they both tell me it is running as good as most any stock KDX with a pipe. I just don't think this bike is ever going to run like the bikes we are accustomed to, and I don't feel like dumping anymore money into this bike. It was fun going through it and making it like new again, but it is probably destined for a new home.

Sounds right. To expect a KDX to run like a overbored MX bike is laughable.

Good luck!

I don't know the signifigance of the A stamp on your cyl...I seem to remember hearing that as well, but have never seen it. It doesn't matter, you can put an F in an A cylinder. A wiseco is like a F. Just ensure good warm-ups.

fuzzy wrote:I don't know the signifigance of the A stamp on your cyl...I seem to remember hearing that as well, but have never seen it. It doesn't matter, you can put an F in an A cylinder. A wiseco is like a F. Just ensure good warm-ups.

I agree completely.

I really wasn't trying to start any problems with this thread, just trying to follow up on something I read on here somewhere, out of curiosity mainly. Thanks to everyone for their input though.

My cylinder was stamped B... that's all I got to say about it.

Interesting. No A,B,C stamps on any of the three cylinders I have. All E series units though. Even so, after a decent amount of use, such a stamp would be irrelevant anyway even if it was there.

That is the exact information I was looking for.

I have to ask Inda, where is this illusive stamp located?

It's been a while... I will have to look for it and get back to you....

Bottom line I don't really know if we are going to keep this bike anyway, my son thinks it is a complete dog compared to his KX 103 mini, and I have to agree. I have had two different friends that have been KDX owners ride this bike, they both tell me it is running as good as most any stock KDX with a pipe. I just don't think this bike is ever going to run like the bikes we are accustomed to, and I don't feel like dumping anymore money into this bike. It was fun going through it and making it like new again, but it is probably destined for a new home.[/quote]


i know what you mean! the kdx is the smallest bike iv had since 88, and ill have to admit, there no loop you over bike, but a good putter.....youll have to learn, on this forum, you have to agree with everyone, and dont expess the way you do things, only expess how you heard over the internet how to do it.........know what i mean? {i think were in the wrong age group]

I think your wacked...

There is no agenda here except to help people with their bikes. You want drama and all that comes with it... you know where that's at... I don't have to tell you.

I see people all the time buy a bike for which they try to make work for a situation in which they are not made for. A KDX is a purpose built bike. If you are not using it for that purpose... there is no point in cutting it down because you made a bad choice. Facts are facts.

BTW... If you think the bike is "no loop you over" bike... you need to learn about tuning. My bike will loop in a heartbeat if I let it.... but it will putt too. If your the nervous type... just get the MX bike and be done with it....

I recall fairly recently a KDX220 smoked a RM250... so the KDX is no slouch if you learn to tune.

have you ever ridden a ktm 300 or a 380? these two will loop you ass in 4th....... if your kdx will loop you...... there is no way i would let you ride my bikes ............. as for your comment about me learning to tune........ ...... i am a certified mechanic, certified welder, cdl licence,class 3 firearms..................... and what is your job? computer what?....... your right though..... dont think a kdx is what its not. i wasnt cutting the kdx down, just telling the truth.... there good bikes, just not what i have been use to power wise........... but it did make my wife a good bike to ride though!

kdxmaniac wrote:have you ever ridden a ktm 300 or a 380? these two will loop you ass in 4th....... if your kdx will loop you...... there is no way i would let you ride my bikes ............. as for your comment about me learning to tune........ ...... i am a certified mechanic, certified welder, cdl licence,class 3 firearms..................... and what is your job? computer what?....... your right though..... dont think a kdx is what its not. i wasnt cutting the kdx down, just telling the truth.... there good bikes, just not what i have been use to power wise........... but it did make my wife a good bike to ride though!

I just rode a KTM300 two weekends ago. I was scared as hell before I got on it. Turns out... it was a dog. Bitch-@ss slow. It would only start pulling late on the throttle. My KDX was scarier. And as Inda's bike, mine will loop my 195+gear fat-@ss in a hearbeat.

So it's definately in the tuning; it doesn't matter what bike it is. Keep on it!

kdxmaniac wrote:have you ever ridden a ktm 300 or a 380? these two will loop you ass in 4th....... if your kdx will loop you...... there is no way i would let you ride my bikes ............. as for your comment about me learning to tune........ ...... i am a certified mechanic, certified welder, cdl licence,class 3 firearms..................... and what is your job? computer what?....... your right though..... dont think a kdx is what its not. i wasnt cutting the kdx down, just telling the truth.... there good bikes, just not what i have been use to power wise........... but it did make my wife a good bike to ride though!

I understand your reasoning but it doesn't really apply here. You could be a great BMW mechanic but couldn't get a Chevy in top tune. What mods have you done?

I don't think being a welder, having a CDL or even being a certified mechanic makes you a good KDX tuner... do you? Some have the patience to work through tuning and some don't. I have been at it a long time and still learning little things here and there. IT isn't my life... it's my job. I have been riding and working on bikes since I was 5... that's 41 years. That's allot of experience.

I had a KTM 250EXC... and yes it was a twitchy bitch... more so than the 300. Too much really for the woods I ride. I never use all that the KDX has and I doubt you would too.

im just saying...you said for me to learn how to tune a bike, thats why i told you what i do for a living is mechanic. im also a certified motorcycle mechanic, i work on bikes in my own shop after i get home. yall are geting the wrong picture here, what i am saying is the kdx is not the powerhouse everyone makes out, ........... but its a great trail bike, but its not going to outrun a 250 up 2 stroke...... yes you can add all the mods you can get, and for what, to out run that stock 250. its not about the speed, i like the torqe of the bigger bikes. i got the kdx to just ride when i dont feel like hanging on to dear life! they are great trail bikes, thats why i got one, plus i needed a bike for my wife to ride.

and to varmit, you say that ktm wouldnt pull untill top? thats strange...... these bikes are built for torqe......