DirtRider . Net MX, SX, Arena Cross, Off-Road Community

This is the text version of DirtRider.Net
Click Here for the Full Version

Pages: 1

KDX200SR -steel liner?
(Click here to view the original thread with full colors/images)

Posted by: motopsycho87---------------------

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!)

Posted by: motopsycho87---------------------

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

Posted by: sr5bidder---------------------

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

Posted by: motopsycho87---------------------

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

Posted by: Rogerdodger---------------------

Quote:

Originally Posted by motopsycho87

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

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

Posted by: motopsycho87---------------------

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

Posted by: Rogerdodger---------------------

Quote:

Originally Posted by motopsycho87

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

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

Posted by: Tom68---------------------

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.

Posted by: motopsycho87---------------------

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?

Posted by: Tom68---------------------

Quote:

Originally Posted by motopsycho87

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?

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.

Posted by: whenfoxforks-ruled---------------------

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

Posted by: julien_d---------------------

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.

Posted by: motopsycho87---------------------

Quote:

Originally Posted by Tom68

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.

so do you know about the kdx200?

Posted by: Tom68---------------------

Quote:

Originally Posted by motopsycho87

so do you know about the kdx200?

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.

Posted by: motopsycho87---------------------

Ah ok!

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

Posted by: EYY---------------------

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?

Posted by: motopsycho87---------------------

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.

Text Version Home

This is the text version of DirtRider.Net Click Here for the Full Version

KDX200SR -steel liner?

This is the text version of DirtRider.Net
Click Here for the Full Version