220SR porting

Non-American model KDX's
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AndrewB
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220SR porting

Post by AndrewB » 12:24 am May 28 2018

Hi - does anyone know if the cylinder porting on the SR is different to the normal 220? I suspect it probably is - the cylinder block has stud mounts for the exhaust instead of spring mounts, and I can't imagine Kawasaki went to all the trouble of retooling just for that difference...

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Jaguar
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Re: 220SR porting

Post by Jaguar » 11:35 pm Jul 14 2019

My 200SR was slightly different than the regular 200 so probably the 220 also has differences. The SR model is more detuned than normal because of its ability to be used on the street. You should figure out the exhaust and transfer port duration in degrees. I would guess that the transfers need to be raised a bit for a more aggressive powerband higher up in the RPM range. If you dont want to change the transfer ports a millimeter or two then consider doing it to the piston edges that transverse the transfers. Make a 45 degree ramp there.
Performance CDI -- KDX motocross mods -- the SR KDX -- expansion chamber analysis---> http://www.dragonfly75.com/moto/

Dan 250sr
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Re: 220SR porting

Post by Dan 250sr » 04:43 pm Aug 01 2019

AndrewB wrote:
12:24 am May 28 2018
Hi - does anyone know if the cylinder porting on the SR is different to the normal 220? I suspect it probably is - the cylinder block has stud mounts for the exhaust instead of spring mounts, and I can't imagine Kawasaki went to all the trouble of retooling just for that difference...
I have 250 sr , same exhaust set up as yours. Mine was a detuned version.. power valve arrangement is different. My sr had no center power valve. Us versions do. Piston was different con rod wrist pin hole different. And nothing available....so now running on kx barrel. Bigger carb , inlet manifold It's not slow now 👍

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