xr250L to R Header Swap Question

[tXRheel]

I finally found an 'R' header to allow me to swap out my 'L' exhaust.

When I went to install the 'R' header, I found it doesn't quite fit. I've read in several places that the 'R' header is supposed to bolt right up.

I have a '92 xr250L and two R headers, one from an '86 and another from a '95. On paper, either should work. What seems to happen is that the pipe from the far cylinder does not come out far enough from the engine before radiusing around the frame down tube. The result is that this prevents the header pipes from seating all the way into the ports. It ends up stopping about 1/2" short.

I know that others have done this mod, anyone have any ideas? What am I doing wrong?

Thanks for any help.

[RedRider3141]

I hate to say it but you are wrong. I have an '88 header on my bike (1994 XR250L), It will NOT fit an L stock or aftermarket muffler. Engine and frame shouldn't be a problem. The R header is fatter than the L make sure you have really twisted and moved it around to try to seat it, also make sure you haven't put the header over the studs in the head, happend to me a few times.

[tXRheel]

Thanks for the quick reply RedRider3141. I know about the muffler fit... I've already got an 'R' muffler ready to go.

I didn't spend a lot of time with it, but it sure seems like the header pipes do not clear the down tube of the frame. There's not much leeway to twist and turn as the exhaust end has to thread back by the engine and then the frame. I'll give it another go tomorrow night.

[jachard]

tXRheel,

Could you do me a Huge favor? SInce you have an "R' header and an "L" header could you measure the OD of the primaries for me? I'm trying to figure out if the previous owner did this swap on my bike.

Thanks in advance!!

James

[tXRheel]

James,

I just took a couple of quick dimensions...

The 'L' Header is in the ball park of 1-3/8" OD

The 'R' Header is in the ball park of 1-1/2" OD

Measured just in front of the header pipe/muffler pipe coupling.

[jachard]

Taylor, Thanks!! Much appreciated.

James

[tXRheel]

Well, I tried it again tonight and it (the 'R' Header) definitely does not fit. The header pipe that wraps around the frame down tube is too close and doesn't allow the ends to seat properly into the ports. I have two different 'R' headers and it's the same with both. I guess it will just remain a mystery.

Plan - B: I got a muffler adapter from Pep Boys and mounted the XR's Only 'R' exhaust to the 'L' header. That was pretty simple.

I also removed the baffle. The bike runs great. Haven't rejetted yet, but initially... much less hesitation, better throttle response, slightly better power (but not much).

[RedRider3141]

Please Send me pics or post of your muffler adapter! I want to put my L exhaust on R headers.

[tXRheel]

RedRider3141 - What you are trying to do (R header to L Muffler) is different than what I did (L header to R Muffler).

All I needed was a muffler pipe adapter sleeve from Pep Boys which slides over the end of my header pipe and increases the outside diameter of the pipe so it fits snug into the R tail pipe.

The R header pipe and the L Muffler pipe should be similar in outside dimension. You may be able to insert both into either end of a pipe sleeve and clamp. Of course it isn't quite that easy, it will take a little planning and simple fabrication, bit it should be doable.

[RedRider3141]

Yeah that is my problem, R header into R Exhaust. I have been looking off and on for a XR250R exhaust stock or aftermarket. I am hesitant to put a stock R exhaust, they are so big and heavy compared to my aluminum L Exhaust.