CR500 Pipe

[BigGreenMachine]

Will it work on a KX500 motor? Rob power? Seems to be the way most go when they do a motor swap to the 250 chassis. What do you guys think?

[gowen]

There has been research on this issue by AJ and hangtime(?). I believe it works, but you have to change the bend. I have a friend that is doing this now and is welding the bend from his KX pipe onto his CR500 pipe... He says it will work.. There is a post here about it..

[BigGreenMachine]

Well what I'm really curious about is how it would affect power delivery. Being that the two motors are different bore and stroke I would think using a pipe from one on the other would limit power somewhat.

[BigGreenMachine]

01 CR500 89 x 79
KX500 86 x 86

[gowen]

It will effect performance, it could be better or worse.. The longer the stinger and section it seems the more mid-top range. I'd guess some low power gains using a cr500 pipe and loss up high.. Here is where it was discussed here.

http://www.kxriders.com/forums/index.php/topic,2525.0.html

[hangtime]

After putting my hands on the zipty pipe I would say this is the best pipe to start with. It starts out very close to being a lowboy pipe, and with a couple of welds you could align the pipe with the new silencer route. You might even try the 99-02 250 silencer. Probably the biggest advantage to the zipty is the pipe routes around the cooling hose on the side of the cylinder. My pipe seems to work nicely, unfortunately I couldn't explain why. Starting with 60 something HP doesn't hurt either.

[MetalMan1011]

For my 250F conversion I used a CR500 Pro Circuit Works pipe.  After a few tweaks and welds I got it to fit.  One of the things I had to do was cut off the end of the pipe that connects with the cylinder and weld a piece from a K5 pipe on, it's outside diameter was  too large to fit the cylinder.  It seems to work very good, but I can't comment on the power differences with a KX with a stock pipe because I have never ridden a regular KX500.     

[BigGreenMachine]

I figured I would have to cut the flange.  How much trouble would the KX pipe be to make fit?

[don46]

The stock KX pipe is a real pain to make fit, look at the picture of my bike you'll see all the cuts and welds to get it to clear the water pipe, radiator, and kickstarter.

[BigGreenMachine]

Yeah but the headpipe looks great! Pro Circuit? The tail of it seems like the harder part to change IMO.

[don46]

Yeah its a Pro Ciorcuit. The tail section was easy, I cut the stinger off the pipe, then used a larger diameter pipe to slip the stinger into, welded on a couple of spring tabs and the cut and twisted so the stinger turned upward. The center section was the most difficult to fabricate. I have a Pro Circuit pipe I'm going to try when the weather gets decent.