KDX200SR -steel liner?

motopsycho87

Member

Dec 26, 2010

152

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• Jun 1, 2011

• #1

I rang the local dealer yesterday asking about getting a new piston and ring set, he told me he had dealth with a kdx200sr before and had a lot of problems getting a piston for it because unlike the KDX200, the SR apparantly has a steel liner as opposed to a plated liner and requires a different piston? True or false? I know theres the possibility it had a liner fitted for an oversized piston but assuming it hadn't, would it originally have been steel or plated?

Thanks!

(i will be ripping into the engine this weekend, just wanted a heads up!)

 

motopsycho87

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Dec 26, 2010

152

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• Jun 1, 2011

• Thread starter
• #2

Also, if they are steel lined, are the pistons any different?

 

S

sr5bidder

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Oct 27, 2008

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• Jun 1, 2011

• #3

the same piston is used in plated or steel sleeved cylinders...

if you look at the wiseco site they spec a sleeve for thier oversizes

 

motopsycho87

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Dec 26, 2010

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• Jun 1, 2011

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• #4

Cool, do you know if the SR comes stock with a liner though?

 

R

Rogerdodger

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Jul 4, 2006

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• Jun 1, 2011

• #5

motopsycho87 said:

Cool, do you know if the SR comes stock with a liner though?

Click to expand...

My Australian model 1989 KDX200F1 (SR equivalent) originally came with a chrome bore. It now has a steel liner as it has been bored out to 240cc.

Cheers

 

motopsycho87

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Dec 26, 2010

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• Jun 1, 2011

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• #6

kinky! what company made the liner / slug combo, and how would you rate it?

 

R

Rogerdodger

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Jul 4, 2006

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• Jun 1, 2011

• #7

motopsycho87 said:

kinky! what company made the liner / slug combo, and how would you rate it?

Click to expand...

I'm not 100% sure who made it, bit I think it's a Wiseco liner. I had the work done by a mob called Serco up in Brisbane back in 1998 who are the Aussie distributor of Wisco pistons. The kit is no longer available here so Kustom Kraft in the USA would be the place to go for a 240 kit if you wanted one.
http://kustom-kraft.com/KAWASAKIKITS.html

I've never had any problems with the 240 kit and the power valves still work OK. However, I don't rev the tits off my bike so that's probably why the big-bore is lasting well! It gives more torque, which suits my riding style. I also have a 35mm PWK carby from the E series KDX fitted rather than the 28mm that came with the bike.

Check out this site about an Aussie KDX200SR fitted with a 240 big bore kit:
http://www.craig.copperleife.com/bikes/kdx/index.htm

Cheers

 

T

Tom68

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Oct 1, 2007

407

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• Jun 5, 2011

• #8

My 250SR was plated but had a 19mm pin, so I changed to a KX conrod and fitted a Gas Gas 300 piston with a bore and replate giving me 285cc.

 

motopsycho87

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Dec 26, 2010

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• Jun 5, 2011

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• #9

Jesus!! Hows that running!?

I take you mean the gudgeon pin? Do you know what the normal KDX pin size is? Reckon they could be interchanged somehow?

 

T

Tom68

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Oct 1, 2007

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• Jun 6, 2011

• #10

motopsycho87 said:

Jesus!! Hows that running!?

I take you mean the gudgeon pin? Do you know what the normal KDX pin size is? Reckon they could be interchanged somehow?

Click to expand...

Runs good, even though the Wossner piston has a side relief that allows the transfer and exh' boost ports to overlap.

18mm pin is standard on KX and KDX250, (19mm on SR 250 only) could have used a bearing to adapt but needed the 5mm shorter KX conrod to have the height right with the Gas Gas piston.

Gotta put a jetski conrod in my IT425 so I can run a 465 piston.

 

whenfoxforks-ruled

Old MX Racer

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Oct 19, 2006

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Merrillville,Indiana

• Jun 6, 2011

• #11

Same piston for a liner or plated bore, but the rings should be different.

 

J

julien_d

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Oct 28, 2008

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• Jun 7, 2011

• #12

Maybe they should be, but they aren't. Not unless you're talking about chrome plating, which we don't really see in dirt bikes.

 

motopsycho87

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Dec 26, 2010

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• Jun 14, 2011

• Thread starter
• #13

Tom68 said:

18mm pin is standard on KX and KDX250, (19mm on SR 250 only) could have used a bearing to adapt but needed the 5mm shorter KX conrod to have the height right with the Gas Gas piston.

Click to expand...

so do you know about the kdx200?

 

T

Tom68

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Oct 1, 2007

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• Jun 14, 2011

• #14

motopsycho87 said:

so do you know about the kdx200?

Click to expand...

No, originally posted to point out that the 250sr was a plated bore and I would think the 200 would have been as well, doesn't mean yours wasn't sleeved by a previous owner, some big bore kits use sleeves.

 

motopsycho87

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Dec 26, 2010

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• Jun 15, 2011

• Thread starter
• #15

Ah ok!

Do you know where I can get the measurements relevant to piston selection atall?

 

E

EYY

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May 22, 2010

159

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• Jun 15, 2011

• #16

If it has the standard 66mm bore and wrist pin size, I'd assume any kdx200 piston from '86 onwards would fit. Didn't the sr's just have different porting and a smaller carb engine wise?

 

motopsycho87

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Dec 26, 2010

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• Jul 1, 2011

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• #17

It has a plated barrel. If anyone can provide me with a picture of there barrel I can point out the differences with my SR barrel.