Hybrid Gene Splicing

Discussion for swapping a KDX motor in a MX frame...
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bufftester
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Hybrid Gene Splicing

Post by bufftester »

Finally getting started on my hybrid build, mating engine and various parts from my 2001 KDX220R to a 2001 KX125 frame suspended with 2001 KX250 boingers. Now that I'm retired I can pursue this project that I have had in mind since 2009 when I flipped my KDX and ducktailed it. Plans for the immediate future are to get it up and running in time for the 2013 Desert 100. My dad and I have ridden in it nearly every year for the last decade (except for a couple of deployments). If everything comes together quickly enough, a short drive down to Portland will be in order to visit RB Designs and drop off the head and carb. Since I didn't have a 125 roller to start with, I have been aquiring the big bits off Ebay and Craigslist, with the plan of reusing a lot of the hardware and stuff from the KDX (the Kawasaki Parts Diagrams are a tremendous help and I have built a spreadsheet that shows every compatible piece between the '96-'06 KDX's and the '99-'02 KX's). Thanks in advance for all the ideas I'm going to blatantly borrow from other's builds! For now the pics are still on my camera, but I have a couple on my phone to upload.
Where I started
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The final result
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First one is the KDX in it's current state, and the 2nd is the new skeleton it is being transplanted into.
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Last edited by bufftester on 06:22 pm Jul 11 2017, edited 2 times in total.
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Julien D
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Re: Hybrid Gene Splicing

Post by Julien D »

Lookin' good! As you can see, there are lots of build threads in here that may help you, or give you some new ideas. Glad you've decided to share the project with us!
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kashola
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Hybrid Gene Splicing

Post by kashola »

Judging by the looks of the KDX, you went for one heck of a ride. :shock:
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bufftester
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Re: Hybrid Gene Splicing

Post by bufftester »

Yeah, suffice to say that when blasting through the E. Washington pucker brush you have to keep a sharp eye out for crazy basalt boulders...I didn't :doh:
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Re: Hybrid Gene Splicing

Post by kdxtreme »

bufftester wrote:Yeah, suffice to say that when blasting through the E. Washington pucker brush you have to keep a sharp eye out for crazy basalt boulders...I didn't :doh:
Ouch been there done that on my brand new ktm in 07 at the d100.
Did I say riding?
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bufftester
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Re: Hybrid Gene Splicing

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Couple more disassembly pics. Engine is now out, going to pull the lighting coil and clutch hub/basket off before I work the swingarm pivot , rear head stay removal and engine mounts. Lighting coil is getting a rewind, and clutch basket going to take out the notches. Still waiting on a few more pieces to arrive (rear axle, front hub, spark arrestor). In the meantime put together a homemade soda blaster, cleans parts up nicely.

Start of disassembly
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Last edited by bufftester on 06:27 pm Jul 11 2017, edited 2 times in total.
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bufftester
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Re: Hybrid Gene Splicing

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A little more work done today, still waiting on Spark Arrestor before I do initial mock up and brackets. Got the engine out, stator removed so I can rewire the lighting coil. Ordered a flywheel puller, and of course the next day Dad says "Hey I have one of those around here somewhere". 15 minutes later I pull one out from his old MR175 circa 1980 (remember those days of having to adjust and gap points?) and the damn thing fits. :doh:
At least now I'll have one to do the same thing to my kids with lol. Also played around with a DIY soda blaster with decent results.

Engine with 12 years of accumulated chain lube and gunk
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The right tool makes all the difference. Read about a lot of folks having trouble removing their flywheels, threaded this on
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and 15 seconds later:
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Very little corrosion given that it spent most of its life in Florida, and the last couple years holding down a corner of the garage
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Lighting coil just begging for a rewind
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The new tool, and the 30+ year old one
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Last edited by bufftester on 06:30 pm Jul 11 2017, edited 1 time in total.
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bufftester
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Re: Hybrid Gene Splicing

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Took the lighting coil off for a rewind (http://www.kdxrider.net/forums/viewtopi ... tor#p97107). Be very careful , the plastic portion doesn't take to heat well. And prying off the epoxy sucks. Then you have to take all the wire off, at which point you understand just how much wire you have to put back on! :? Whole process only took about an hour from the time I pulled it off the stator to the time it was ready to resolder.

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Last edited by bufftester on 06:34 pm Jul 11 2017, edited 1 time in total.
kdxtreme
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Re: Hybrid Gene Splicing

Post by kdxtreme »

bufftester wrote:Took the lighting coil off for a rewind (http://www.kdxrider.net/forums/viewtopi ... tor#p97107). Be very careful , the plastic portion doesn't take to heat well. And prying off the epoxy sucks. Then you have to take all the wire off, at which point you understand just how much wire you have to put back on! :? Whole process only took about an hour from the time I pulled it off the stator to the time it was ready to resolder.

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Cool I'll bring mine down to ya to do. :lol:
Did I say riding?
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bufftester
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Re: Hybrid Gene Splicing

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Coil is done and ready to go back in. Box of parts showed up on doorstep yeesterday. Now just need some time off work to get in the shop.
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Last edited by bufftester on 06:37 pm Jul 11 2017, edited 2 times in total.
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bufftester
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Re: Hybrid Gene Splicing

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Just had time to drop in the shop and drop off parts. Quick fit check of the subframe, SA,tank...mostly just because I'm anxious to get started
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Last edited by bufftester on 06:39 pm Jul 11 2017, edited 1 time in total.
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Re: Hybrid Gene Splicing

Post by bufftester »

Made a little more progress this weekend between work and Super Bowl. Got the engine case drilled for the swing arm, the swing arm cut, test fit the engine, got my new front wheel in and changed bearings in it, cleaned up a bunch of parts. This week is fabricate the engine mounts and work on the airbox adapter plate.

Engine with 15mm hole
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Engine with 17mm hole
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Test fit in frame
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Swing arm (cut with angle grinder and cut-off wheel, cleaned up with file)
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Last edited by bufftester on 06:45 pm Jul 11 2017, edited 1 time in total.
Roadhazardguy
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Re: Hybrid Gene Splicing

Post by Roadhazardguy »

Cool build! I just might have to build one of these one day.
Tony
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1980 KD 80
1989 ATK 406
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bufftester
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Re: Hybrid Gene Splicing

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Had a rare day off this weekend so got a little bit done. Cut the swingarm bushings and finished the swingarm fit, then pressed in new swingarm bearings. While at the bearing gig dropped new ones in the rear wheel and the shock linkage. The shock will get new ones as well when I reassemble it. Tore the shock down to rebuild, but didn't have enough oil on hand so gotta sneak out to the bike shop at lunch tonight. Finished cleaning up the remnants of the old engine mounts and sourced some 1/8" steel plate to make new ones with, along with some aluminum plate for the airbox mod. Mounted up the radiators to see if I could reuse the stock KDX overflow reservoir, but won't fit behind the radiator without altering the shroud and support arm, so it just gets left off for now (I haven't seen anyone else running one on a hybrid, but thought I'd try anyway). Mocked up the engine and exhaust for mounts and marked them and the frame hoops. Hope to have engine mounts finished up this week.

Rear shock apart
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New rear wheel bearings
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rear head stay removed, pic before final sanding/filing
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mocking up engine/exhaust mounts
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stock pipe stinger extends a little far, so will need to do a little work on the pipe/spark arrestor joint to get it clean. rebuild of the forks will be done tomorrow after I get more oil! Since I didn't have a complete bike to start with I have a bunch of little odds and ends to order, but getting excited to finish the build.
Last edited by bufftester on 06:50 pm Jul 11 2017, edited 1 time in total.
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Hybrid Gene Splicing

Post by rbates9 »

Looking good.
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bufftester
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Re: Hybrid Gene Splicing

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So while I was futzing around with my airbox, and generally not wanting to dig out my jigsaw and drill for the evening, I was staring at the two airboots (kx and kdx) over my mac and cheese..."hmmmm", I thought, "that kdx boot looks like it will fit inside the kx one" And it does...so I'm wondering if I just cut off the round portion that fits over the carb off the kdx and permatex it inside the kx boot I can skip plates and aluminum and drills hooray! I remember seeing someones build where they had a custom ring formed out of metal, would this work??? I guess I could try and worst case I end up making the plate and sourcing a new kdx boot. Any suggestions? was thinking cynacrylate tire glue like we used to use in the RC days, it bonds rubber well and stays flexible.
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Last edited by bufftester on 06:51 pm Jul 11 2017, edited 1 time in total.
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doctord23
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Re: Hybrid Gene Splicing

Post by doctord23 »

I did exactly what you are contemplating.
It is a little difficult to get on the carb like that so I put the kdx piece on the carb and then slid the kx boot over.
My Team Green:
2002 KX-KDX 220
2000 KDX 220
2003 KLX 300 DS
1988 White KDX 200C3
1984 KX500 (original owner)
1996 Honda Magna V4
2017 Honda Africa Twin DCT
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bufftester
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Re: Hybrid Gene Splicing

Post by bufftester »

Doctord23, has it worked out well? Any issues other than just getting it on? Did you trim the ribs off the KDX piece first? Just happy I can bypass another bit of fabrication without having the build suffer any.
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Re: Hybrid Gene Splicing

Post by doctord23 »

It has worked out fine.
I cut it just past the interior step so it would stop at the carb back edge and trimmed off the exterior back lip so the kx boot would slide over if that makes sense.
The kx boot is a little long and meant for a lower carb position so it takes a little work to get it on even before you tighten the clamp.
Otherwise it will want to slide back as you tighten the clamp.
If I remember right, I may have used the kdx clamp.
Last word of advice is that the boot is really tight to the shock spring so you have to adjust and it works best with the stock reed block.
The v-force pushes the carb back more.
My Team Green:
2002 KX-KDX 220
2000 KDX 220
2003 KLX 300 DS
1988 White KDX 200C3
1984 KX500 (original owner)
1996 Honda Magna V4
2017 Honda Africa Twin DCT
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bufftester
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Re: Hybrid Gene Splicing

Post by bufftester »

Makes perfect sense, that's how I was picturing cutting it. Thanks for the advice!
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