KTM + KDX = my new project

Discussion for swapping a KDX motor in a MX frame...
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DRoCksks
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KTM + KDX = my new project

Post by DRoCksks »

I picked up a nice 2002 KTM 125 SX last November. I got it thinking it had a cracked cylinder. It turned out to be assembled incorrectly and ran fine with that problem made right. I found out the clutch was shot immediately after and picked up a used unit for a good price. Afterward it seemed to be good to go and I patiently waited for the snow to melt to try it out.

Fast forward to last Saturday... I got 3 minutes of riding on it before it locked up...bad rod bearing. After a little looking at the 2 bikes I decided to pull them both apart and test fit the engine from my E series 1989 KDX to the KTM swingarm. Pivot bolt is the same on both and the width is very close with there being just a small spacer needed between the swingarm and engine case! I'll try to get some pics...it was too dark earlier.

My one question is, is it OK to find a washer to use as a spacer or do I need something more elaborate?
DRoCksks
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KTM + KDX = my new project

Post by DRoCksks »

Here are a few pictures, I know its dirty and the pictures suck but I'm still in the planning phase. You can see how close the existing mounts are in the pictures...its frustratingly close. Thats the stock carb on the ktm airbox boot. I think that I can force it or heat gun it since its soft pliable rubber all the way to the box. Also I tried to get a picture of the swingarm to case clearance. Its less than 1/8 inch of a gap.

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doctord23
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Re: KTM + KDX = my new project

Post by doctord23 »

Adding a spacer shouldn't be an issue. Before you do, you will want to look closely at the alignment of the countershaft and rear sprocket.
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DRoCksks
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KTM + KDX = my new project

Post by DRoCksks »

Already did that and test fit the chain but I will be careful when I do more permanent mounting. Thanks!
chkdx
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Re: KTM + KDX = my new project

Post by chkdx »

Nothing wrong with using a washer as a spacer, but I would recommend using a hardened ( grade 8 ) washer.
GI_JO_NATHAN
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Re: KTM + KDX = my new project

Post by GI_JO_NATHAN »

chkdx wrote:Nothing wrong with using a washer as a spacer, but I would recommend using a hardened ( grade 8 ) washer.
+1
You don't want anything that's going too compress.

Cool project!
DRoCksks
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KTM + KDX = my new project

Post by DRoCksks »

Started on motor mounts today, got the top done. No pictures because its boring looking... :grin:

Also got the front half way done but I'll need to pull the engine out to finish them... Still nothing to look at
KarlP
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Re: KTM + KDX = my new project

Post by KarlP »

Sounds like a fun project.

Watch that pipe and airbox boot, make sure they line up before finalising mounts other than the swingarm
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DRoCksks
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KTM + KDX = my new project

Post by DRoCksks »

Found an h series pipe used and it will work with a little adjustment. Also had to re do my motor mounts to lower the engine. The carb to airbox fit is better and the tank will need less molding to fit around the head. I'll try to get more pics when I have more progress that you can see.
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Re: KTM + KDX = my new project

Post by GI_JO_NATHAN »

Nice progress!
DRoCksks
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KTM + KDX = my new project

Post by DRoCksks »

It lives! Mostly at least, haven't ridden it yet but it runs. Minor setback when a mouse nest blew out of the pipe and plugged it up. When the weather gets nicer I hope to pull it out and do a good cleaning on it.
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KTM + KDX = my new project

Post by DRoCksks »

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KTM + KDX = my new project

Post by DRoCksks »

Got it rideable! Just a short lap around the block but I love it so far. Feels much more modern and comfortable for me. I need to add one more mount for the pipe to keep it off the motor but that won't take much. Also added my green Shox Sox to keep a little Kawi color on it...may add the handgaurds too but may plasti dip them black first.
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Julien D
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Re: KTM + KDX = my new project

Post by Julien D »

good work! I like it!!

Probably the first time I've ever heard anyone refer to a KTM chassis as comfortable, though, LOL! :mrgreen:
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DRoCksks
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KTM + KDX = my new project

Post by DRoCksks »

http://s250.photobucket.com/user/DRoCks ... h.mp4.html

Short,(12 minute) kinda boring video that proves it works... Sorry its not that awesome of riding but I'm still sorting it out and its about 98%
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