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Torque pipe for KDX250?

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Hey all, I've searched and searched and the only pipe I can find for my 1994 KDX250 is a FMF K24 which is a fatty, I really want a gnarly, but no one makes one, Will a 1995-1996 KX250 gnarly fit? Fit with a little massaging? Any other ideas for a monster tractor pipe? Does the K24 give me the tractor I want or will it be peaky?

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Will a 1995-1996 KX250 gnarly fit? Fit with a little massaging? Any other ideas for a monster tractor pipe? Does the K24 give me the tractor I want or will it be peaky?

It will tractor. I ran one with a '98 cylinder and it made great bottom-mid power with my setup. Even with a mismatch at the flange it performed well. The 95-96 pipe will have a smaller diameter inlet than your kdx exhaust port so as is that may not be a good choice... but a few minutes with a grinder would fix that.

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Thanks all for the info, TT is the best! It does tractor now, but I have a heavily smashed Fatty on it now, smashed at the first u turn and at the fat section, bought it that way, and it seems to go a little flat before hittin the pipe, not sure if it is sticking PV, pipe, or something else. Tractors like crazy, just doesn't seem smooth enough through the RPM range. Already played with the jetting, ground the slide, still waiting on a leaner needle (I am super anal about jetting and carb tuning, I used to lathe my needles to get rid of lean spots on my street rods). Waiting on a top end gasket kit so I can check top end and KIPS, also need to do a compression check, but haven't located my tester yet. I want smoooooooth transition!

Edited by TurboStew

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The 95-96 pipe will have a smaller diameter inlet than your kdx exhaust port so as is that may not be a good choice... but a few minutes with a grinder would fix that.

:lol: Do you mean that the OD is the same for KDX and 95 KX but the ID is smaller on 95? Just enlarge the ID? Does the pipe dimensionally fit otherwise? Mount locations as well?

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Hey all, I've searched and searched and the only pipe I can find for my 1994 KDX250 is a FMF K24 which is a fatty, I really want a gnarly, but no one makes one, Will a 1995-1996 KX250 gnarly fit? Fit with a little massaging? Any other ideas for a monster tractor pipe? Does the K24 give me the tractor I want or will it be peaky?
You'll be very happy with the Fatty, it compliments the ignition curve, smaller carb, and porting of the KDX250 extremely well. Combine that with the thinner KX head gasket, proper jetting and a leaner slide, and Boyesen Power Reeds, and you'll have an engine that pulls great from just above idle all the way to the top, with a sweet low-to-mid powerband. It will be a very tractable engine that excels at grunting up hills and such. Mine would grunt up hills in second and third that other bikes had to scream up in first and second.

I used a Powercore silencer. The mounts won't line up with the KDX frame, but that was an easy fix. I used a twelve inch long by one inch wide strip of 1/16" steel bolted to the frame mounts, and drilled new holes in the metal strip to line up with the silencer mounts.

FMF did make a torque pipe for that engine, but oit sucked. It was just a clone of the stock pipe's power curve, although a bit stronger just off idle. The Fatty is superior in every way.

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:lol: Do you mean that the OD is the same for KDX and 95 KX but the ID is smaller on 95? Just enlarge the ID? Does the pipe dimensionally fit otherwise? Mount locations as well?

cant say for sure on the mounts, but i am sure they would be pretty close. The newer pipes have a smaller i.d. than the early ones. The flange i.d. on the kdx fatty was quite a bit bigger than the port on my '98 cylinder. The '96 oem pipe i have has the same small id as my 98. If you used a newer pipe on a older cylinder i would grind the flange to match the port. I dont have kdx fatty anymore or i would compare it to the '96 pipe for you. I now use a '89 fatty cuz i since put the engine into a kx500 chasis.

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