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Do i need to replace piston, is it really bad ?

Posted: 01:45 pm Mar 30 2017
by raver8
Hi all, guys, i just got my kdx 200 with 15 000 myleage
nice power and tear off the exaust pipe and i see this ... is it really bad :blink: ?
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Re: Do i need to replace piston, is it really bad ?

Posted: 02:11 pm Mar 30 2017
by Tyl3r
:hmm: looks pretty bad to me

Do i need to replace piston, is it really bad ?

Posted: 02:11 pm Mar 30 2017
by pumpguy
Piston pix don't look good at all. I would consider piston and rings to be consumable items.

More importantly, how is the cylinder wall? Could be worn and scored similar to piston.

IIWM, I would pull the cylinder to have a look see and measure the bore. Measurements should be taken in 3 places, top, just above top of exhaust port, and a bit below the bottom of the exhaust port.

Stock bore for H Series 200 is 66.026 - 66.041 mm.

My guess is cylinder is scored too and probably needs a re-plate.

While the cylinder is off, you should clean out the KIPS. For a re-plate, you will need to remove all the KIPS valves before sending out to plater.

Oh, if you don't have a manual, by all means get one. It's the most useful tool you can have.

Good luck.

Re: Do i need to replace piston, is it really bad ?

Posted: 02:32 pm Mar 30 2017
by Timtee
Looks good to me. Just hit it with some green scotch bright pad and you should be good to go.

Re: Do i need to replace piston, is it really bad ?

Posted: 02:48 pm Mar 30 2017
by raver8
pumpguy
thank your for advice i'm appreciate it. i hope walls don't gone very badly (

Re: Do i need to replace piston, is it really bad ?

Posted: 04:05 pm Mar 30 2017
by KDXGarage
It looks bad to me. I would want to see the cylinder walls.

Timtee, are you serious?? :shock:

Do i need to replace piston, is it really bad ?

Posted: 04:45 pm Mar 30 2017
by o/d
Looks real bad to me. I would expect to see the same scoring on the cylinder walls. Time for a new top end. Then consider bottom end based on what you see once cylinder is removed.
Similar or worse than the piston in my new to me bike. My cylinder needed welding & re-plating. Opted to rebuild bottom end, which I'm in the middle of now

Re: Do i need to replace piston, is it really bad ?

Posted: 05:54 pm Mar 30 2017
by Timtee
Jason wrote:Timtee, are you serious?? :shock:
No,100% sarcasm.

I would rebuild the bottom end as well. That much dirt has likely worn the bottom end and I wouldnt trust a new top end with it.

Re: Do i need to replace piston, is it really bad ?

Posted: 07:00 pm Mar 30 2017
by KDXGarage
OK, good. I was wondering. We have a fine selection of smileys on the right. LOL :lol:

Re: Do i need to replace piston, is it really bad ?

Posted: 01:14 am Mar 31 2017
by javjacob
I am going to recommend Millennium to get the cylinder replated. Millennium also cleans the KIPS for a little extra money if you don't want to mess with it.

Re: Do i need to replace piston, is it really bad ?

Posted: 03:42 am Mar 31 2017
by KDXGarage
1992 KDX200SR

guy won't put his country?? not USA, so not Millenium.

This is why I ask that people put their country so you don't waste people's time when they give advice that is for their country, not yours.

no mention of year
no mention of which country
no mention of SR model (in his profile)

Re: Do i need to replace piston, is it really bad ?

Posted: 10:32 am Mar 31 2017
by javjacob
I never even realized my profile doesn't show my country or state. I could have sworn it atleast had my state.

Problem fixed now.

Re: Do i need to replace piston, is it really bad ?

Posted: 02:32 pm Apr 02 2017
by raver8
Hi guys, thanxs for your comments, i do like sarcasm
it's like refreshing kick in the ass - "do it, find money this is what you ever want ...
yeah bt%h this is 25 y old ... wheel of fortune... and you knew it ..." ))
but still love this bike ...

can enyone help - la sleeve for kdx 200 R can fit for SR
i mean ... in R version doesn't have middle window valve

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p.s. sorry for personal info . kawasaki kdx 200 sr 1991 .

Re: Do i need to replace piston, is it really bad ?

Posted: 02:55 pm Apr 02 2017
by 6 Riders
Don't sleeve it. Just have it replated. Any real bad gouges can be welded up before plating.

Re: Do i need to replace piston, is it really bad ?

Posted: 03:33 pm Apr 02 2017
by raver8
why ? sleeve are cheaper than welding

Re: Do i need to replace piston, is it really bad ?

Posted: 03:40 pm Apr 02 2017
by 6 Riders
Sleeves don't last as long. You should only use a sleeve if the cylinder is beyond repair, even then you are better off buying another cylinder than sleeving.

Re: Do i need to replace piston, is it really bad ?

Posted: 04:08 pm Apr 02 2017
by raver8
thanx for info. cylender got little crack above valve

Re: Do i need to replace piston, is it really bad ?

Posted: 06:55 pm Apr 02 2017
by pumpguy
Platers are usually able to do repair welding to damaged cylinders prior to re-plating. It's part of their surface prep work.

I would suggest you send pictures and discuss this with your chosen plater.

Might cost a little more, but IMO, it's a better way to go than sleeving.

Re: Do i need to replace piston, is it really bad ?

Posted: 03:26 am Apr 03 2017
by raver8
this is crack . sleeve for me in 2 times cheaper than welding

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Do i need to replace piston, is it really bad ?

Posted: 11:10 am Apr 03 2017
by pumpguy
Kind of looks like this cylinder has been sleeved before. There's a definite line between the 2 surfaces of the gouged out area, if I'm understanding the picture correctly.

When all is said and done, you will need a new piston and recondition the bore by either re-sleeving or plating. I would suggest you discuss the merits of each with your chosen supplier and go from there.

Also, make sure all the KIPS valves are in good condition and the main exhaust valve won't foul the piston when in closed position.