KX Riders

Maintenance & Technical => KX500 Original => Topic started by: BigGreenMachine on March 30, 2007, 01:20:16 AM

Title: CR500 Pipe
Post by: BigGreenMachine on March 30, 2007, 01:20:16 AM

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?

Title: Re: CR500 Pipe
Post by: gowen on March 30, 2007, 01:47:39 AM

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..

Title: Re: CR500 Pipe
Post by: BigGreenMachine on March 30, 2007, 02:30:32 AM

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.

Title: Re: CR500 Pipe
Post by: BigGreenMachine on March 30, 2007, 02:45:58 AM

01 CR500 89 x 79
KX500 86 x 86

Title: Re: CR500 Pipe
Post by: gowen on March 30, 2007, 02:54:59 AM

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

Title: Re: CR500 Pipe
Post by: hangtime on March 30, 2007, 03:44:54 AM

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.

Title: Re: CR500 Pipe
Post by: MetalMan1011 on March 31, 2007, 07:01:16 AM

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.     

Title: Re: CR500 Pipe
Post by: BigGreenMachine on April 01, 2007, 06:07:33 AM

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

Title: Re: CR500 Pipe
Post by: don46 on April 01, 2007, 01:24:01 PM

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.

Title: Re: CR500 Pipe
Post by: BigGreenMachine on April 01, 2007, 11:37:44 PM

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

Title: Re: CR500 Pipe
Post by: don46 on April 02, 2007, 03:59:59 AM

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.