2009 kx 250f

Discussion for swapping a KDX motor in a MX frame...
89kdx200
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2009 kx 250f

Post by 89kdx200 »

So i have a 96 KDX and was thinking about upgrading forks and shocks until I found a 2009 kx250 with a blown engine. Now I think the best option would be to swap my 200 into the 09 chassis. What's the consensus on that frame for trail riding? Or is the older steel frame the best?
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Re: 2009 kx 250f

Post by KDXGarage »

I think one difference is welding aluminum instead of steel.
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Re: 2009 kx 250f

Post by doakley »

Sure as heck tempting. Know anyone with a KXF you could ride? FWIW I have a friend with a KX450F who loves it in the woods. Also see quite a lot of them at hare scrambles and some at enduros.
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Re: 2009 kx 250f

Post by Yeahthebikes94 »

Would love to see this build! Havent seen many kdx hybrids in a more modern frame than 2005.
As far as AF and SF are concerned, Af tends to be stiffer, and generally slightly lighter. Sf has a bit more flex which some riders like for the trails.
Welding Af is different to steel as you are probably aware.

Please go ahead with this build, Im sure itl be awesome
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2009 kx 250f

Post by 89kdx200 »

Awesome thanks for the input. If the bike turns out to be clean I'll be buying it for sure. Aluminum welding and fab won't be an issue. I'll keep you guys posted.
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Re: 2009 kx 250f

Post by KDXGarage »

Did you see where a new cradle has to be welded in due to the pipe exit from the engine? Someone correct me if I am wrong on that. Sorry if you are a master craftsman. Most of us are not, but a few have bought first, thought long and hard about it second.
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89kdx200
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2009 kx 250f

Post by 89kdx200 »

Ya I know the main tube is is to low and will need to be moved up at least 4 inches. That stuff isn't to big of a deal it's kinda what I do.
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Re: 2009 kx 250f

Post by bufftester »

The aluminum frame has been done on here IIRC, and certainly is in the realm of possibility. Would make for a very nice trail bike.
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Re: 2009 kx 250f

Post by Tyl3r »

The aluminum fab work kept me from wanting to use a newer aluminum frame for my hybrid. If you can do the work, I'd love to see the results!
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Re: 2009 kx 250f

Post by Julien D »

I've seen a few nice aluminum frame builds. Mostly around the CRF250, but I imagine the required work here would be similar. Personally I prefer a steel frame for trails, they are less rigid. That's strictly personal preference, obviously. The aluminum frames sure are pretty!
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2009 kx 250f

Post by 89kdx200 »

So i checked the VIN on the bike, its currently reported as stolen. oh well.
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2009 kx 250f

Post by 89kdx200 »

I found another bike local with a blown engine. Its a 2007 YZF250. Any one have any info on major issues fitting In my 96 KDX engine.
The big ones will be the swing arm width and exhaust but i dont feel that it will be that different?? input??
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2009 kx 250f

Post by 89kdx200 »

Picked up a new project bike yesterday. 2007 Kx250f

[url=http://s1328.photobucket.com/user/ls1ve ... f.png.html]Image[/url

EDITED by Jason to show picture. I can't see it on my laptop. I had to go fiddle around and dig it out from photobucket on some link copy and paste.

Image
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Re: 2009 kx 250f

Post by KDXGarage »

Congratulations. Good luck on the work.
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2009 kx 250f

Post by 89kdx200 »

Image

Image

Image
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Re: 2009 kx 250f

Post by Tyl3r »

Those last two pictures are what scare me the most! haha Looks good, that thing is going to be sweet. Are you doing all of the aluminum fabricating and welding yourself?
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89kdx200
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2009 kx 250f

Post by 89kdx200 »

Ya I'll be making up the mounts tomorrow and then on to welding. I'll also need to add approx 1" to the pipe to get it into the engine just right. Then onto wiring.
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Re: 2009 kx 250f

Post by bufftester »

Adding an inch to the pipe will sacrifice a bit of your top end, but you'll get some of that back in torque. An inch is a long way in 2 stroke pipes.
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Re: 2009 kx 250f

Post by Tyl3r »

Nice man, keep us posted on the progress!
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Re: 2009 kx 250f

Post by Timtee »

Definitely interested in how the airbox/boot plays out.
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