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2005 kx200ac
Posted: 06:00 pm Jul 12 2013
by De250r
Kinda stumbled on a gold mine. Talking with a buddy on a ride last weekend about my other friend not being able to ride due to bad rim on his klx. He said will one off an 06 250f work? Where did y get that? Well aftera week of negotiating I traded him my go cart frame that I paid $172 for for everything to put back together a rolling chassis. All but motor and carb. Needless to say my buddy still needs a wheel:) sorry Gary maybe u can ride it when I get it together.
I already have put together a 84 kdx200/89kx500 hybrid that just needed finishing.another friend was gonna finish and ride it but he hasn't yet. So I'm thinking getting that bike back and putting the ac 200 motorin the new frame. I've got a couple cb750 street bikes that I'm looking to put a motor out of in a on/offroad bike so the kx500 frame would work well for that project down the road.
So I'm thinking:
6-700 suspension rebuild/valve tops
300 plastic controls and stock pipe to modify.
So for hopefully not much more than 1k I should have a cool light street legal(oh ya i live in vt and we can title anything) air cooled off road weapon and relieve my klx250s of serious trail duties which it try's so well to do and does so very well just 80lbs to heavy and not suspended well enough.
I'm all set to get my cb750 bobber frame powder coated at work so im gonna sneak this one on the line behind it.
Getting excited. Ill post pics when I have more than just a pile of parts in the bed of my truck. Oh here's my inspiration
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Re: 2005 kx200ac
Posted: 06:15 pm Jul 12 2013
by De250r
This build has been talkedabout and contemplated. Excited to start
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Re: 2005 kx200ac
Posted: 06:37 pm Jul 12 2013
by Julien D
So aircooled motor in 250f chassis? Sweet!
Re: 2005 kx200ac
Posted: 07:38 pm Jul 12 2013
by De250r
I just ran across a Yamaha blaster motor in trade for another motor. It's not a kdx but equivalent. Center exit exhaust so u would have to mod the frame wich I was ready for to do the lc swap. So it would b ready to do the lc swap. I will get a stock 200 pipe and silencer to mod for whatever engine I choose. It will fit way better on the blaster motor. Will probably only have to make a little manifold to come off the blaster head to fit the kdx pipe. Might go this route the more I think about it. That way I can keep my original hybrid intact
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Re: 2005 kx200ac
Posted: 08:44 pm Jul 12 2013
by bufftester
I've talked about this before, and have kicked it around my head for a year or so, that would be a cool ride and certainly would turn a few heads as they try to figure out how you're getting by missing your radiators! lol. Can't wait to see your progress.
Re: 2005 kx200ac
Posted: 11:05 pm Jul 12 2013
by De250r
The blaster motor would fit better in the 500 frame better due to center exhaust. Neither frame will need mods. So I'm gonna bring both here and start mocking up. I've been reading about these hybrids for awhile and it's so cool to have one fall in my lap
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Re: 2005 kx200ac
Posted: 08:34 pm Jul 14 2013
by De250r
I'm gonna use the kdx motor in the 250f frame. Going to pick it up at my buddy's house tomorrow hopefully.
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Re: 2005 kx200ac
Posted: 05:05 pm Jul 15 2013
by bufftester
Looking forward to this build as it has been one I have been contemplating. Just imagine the looks it would get out in the woods

Re: 2005 kx200ac
Posted: 12:10 am Jul 16 2013
by De250r
Just talking to my buddy's on last weekends ride they were looking at me like that. They were telling me I should just put the 250f suspension in my 250s wich is doable I can machine whatever. But two bikes is always better then one well suspended one right. Don't get me wrong I looked into it and maybe when I find another one ill put some in my klx but I really want a 200lb trail bike.
So I started to sort things out. I didn't realize when I picked it up but I didn't have the subframe. But I texted and he went and found it. I gotta go pick up my other hybrid tomorrow to pull the motor.
I nee to tear into my cb750 motor too so we will see wich gets stared first
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Re: 2005 kx200ac
Posted: 07:43 am Jul 19 2013
by De250r
So he found the rest of my parts so know I can put it back together as a roller. Have got a list of parts already started.
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Re: 2005 kx200ac
Posted: 09:51 pm Jul 24 2013
by De250r
So finally some progress. I picked up the 500 hybrid and pulled the motor. You gotta love the simplicity. I pulled the head off to discover its been sleeved and it 67.50 mm and the bore and piston look good. I'm gonna mic up after work tonight. I tore it down to mainly check lower rod bearing and it's nice and tight. Again u gotta love the simplicity. The motor seemed like it was dragging when turned over before I toke it apart but I lubed up the mains an it spins nice as well. A guy on cl called me back finally and has a stock pipe and silencer for a 97 for $50 I'm going to get on sat
The engine slides right in like it was ment for the frame. I Just gotta drill out the Swingarm hole in block. I got the bit already. This bike might go together quicker than I thought.
Oh ya made my first bling for it
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Re: 2005 kx200ac
Posted: 08:51 am Jul 25 2013
by De250r
So my cylinder/piston looks good but there is .006-.007 clearance so looks like I'm gonna b at 68.00 mm. I'm gonna split an do main bearings while I have it apart and check everything all out. Will b nice to know its all fresh anyway
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Re: 2005 kx200ac
Posted: 02:01 pm Jul 25 2013
by fuzzy
Sweet!
FWIW the blaster motor doesn't hold a candle to the KDX motor, and might have issues at it's geared for a small tire
Re: 2005 kx200ac
Posted: 04:31 pm Jul 26 2013
by De250r
Got it mocked up sorta. Ordered bearings and piston and what not.

It's gonna fit nice. Except when I bored the rear hole out it broke through to the tranny so it will need to b sealed up now. If I didn't need to split cases b4 now I def have to next time I would use the skinnier bolt and made spacers for it.
I started to order other parts as well. Ill b a busy boy when all this comes in.
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Re: 2005 kx200ac
Posted: 06:45 pm Jul 26 2013
by De250r
Order order order card is starting to sizzle
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Re: 2005 kx200ac
Posted: 12:28 am Jul 27 2013
by De250r
So I've decided to buy nice used monster edition plastics. That way it will look pretty good but not so good that i won't wanna mud bog and brush ride it.

Finished my brake pad tonight
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Re: 2005 kx200ac
Posted: 01:52 pm Jul 27 2013
by De250r
Lucked out. The case has a void in the casting that felt like the tranny but its not so no worries there. I got it all aligned with the Swingarm bolt all the other mounts I can build out of flat stock. Everything lines up straight. Ill build some cool aluminum truss's tho
My wife was my sense of reason today. She said why drive to Massachusetts and pay for a pipe u don't want then modify it to figure out u need a new one. Just save the time and buy a new one. So looks like in gonna buy a new gnarly pipe and silencer and adapt the I let for the side exhaust. I think ill build a cool trim ring that will bolt over the tig welds so I don't mess up the plating as little as possible. If I do it right it will still be about the same length. Gonna b scary to take the cut off wheel to a new fmf. I called fmf and they don't build custom pipes. It will obviously flow better than the stock 84 exhaust.
I love my wife:)
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Re: 2005 kx200ac
Posted: 01:54 pm Jul 27 2013
by De250r
Ill need to mod the airbox boot. Might look into a newer carb.
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Re: 2005 kx200ac
Posted: 08:44 am Jul 29 2013
by De250r
Def gonna look into a newer carb. I've got everything ordered pretty much now I wait for the ups guy. There is some stuff I have to get done this week thou. Motor mounts. Strip the frame for this and my cb750 for powder coat. . Gonna do gloss black pc on everything. Then spray different parts another color.
It's coming together but antsy for all my presents to arrive.
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Re: 2005 kx200ac
Posted: 07:27 pm Jul 30 2013
by De250r
I got the motor mounts figured out today. Everything lines up almost perfect. There will b no frame mods to put engine in so I could bolt the 250f engine back in. Don't know why I would want to. Almost ready to tear it down for paint. Waiting on parts parts and more parts.
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