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 »

Spent this morning before work servicing and rebuilding the rear shock. Now back together with a fresh batch of 7W and 145PSI Nitrogen charge.
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Last edited by bufftester on 06:53 pm Jul 11 2017, edited 1 time in total.
Roadhazardguy
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Re: Hybrid Gene Splicing

Post by Roadhazardguy »

Very nice! I'm gonna have to do one of those for the first time, when I get to that point...

From what ive seen they actually don't look as bad to rebuild as you would think.
Tony
1988 KDX 200
1980 KD 80
1989 ATK 406
1984 RM 500
1980 KZ 1300
2008 SM450R
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bufftester
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Re: Hybrid Gene Splicing

Post by bufftester »

Pretty easy really, hardest part is getting the lower cap off as you pry it up with a couple allen wrenches. Was easier than the forks (which I still have to do).
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Tedh98
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Re: Hybrid Gene Splicing

Post by Tedh98 »

How did you go about bleeding the shock? I haven't serviced a shock yet, but from what I've read, that is the key part of it all.
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bufftester
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Re: Hybrid Gene Splicing

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I did a lot of internet searching on that, and in the end followed the procedure in the cyclepedia manual (all the stuff I found was just a variation of that process. Basically you fill the reservoir side halfway and insert the bladder and circlip. a bit of oil spills over, but you essentially are eliminating most of the air in the reservoir that way. Then you fill the shock body to spec (for the '00 KX250 shock I used it was 52mm from the top), insert the piston assembly until it just seats the o-ring and pump the shock several times to work the air out of the piston and oil galleys. Then fully insert the piston, put in the circlip, tap the end cap on and turn it right side up and cycle the shock some more. Leave the rod fully extended for 5 mins or so to let any residual air work up. Then hold the shock so the bleed screw is facing up and slowly remove it (watch for the squirt!) and let it drain until it stops. If it doesn't drain then you just add oil through the bleed hole till it does. then bleed screw in and charge the bladder with nitrogen. I did the bleed screw a couple times to make sure, you can feel when you cycle the rod if there's any air in there as it will kind of skip instead of moving smoothly.
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bufftester
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Re: Hybrid Gene Splicing

Post by bufftester »

So I just got a small box of odds and ends (collars, gaskets, hardware) so I think I now have everything to finish up, and should be getting the engine mounts welded up this weekend. I ordered everything from MotoSport, have always had good luck with them and prices are usually good. I had 17 items in my order, all for either a KX or KDX, and they all arrived quick, heck Motosport even threw in a bunch of stickers, and a 2013 calendar.....all ATV photos :doh: lol
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bufftester
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Re: Hybrid Gene Splicing

Post by bufftester »

Finally got the time to weld up engine mounts. Also tackled all the bearings (swingarm, linkage, shock..already did the wheels earlier) and the fork seals.
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Last edited by bufftester on 06:56 pm Jul 11 2017, edited 1 time in total.
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bufftester
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Hybrid Gene Splicing

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Trying to find time to finish my build between the long hours at work. Had a couple this morning and started reassembly. Got the front end on, next is finishing radiators and plumbing (the shop seems to have eaten one of my hoses and various other parts and tools...guess I really should clean it one of these days). Still have to work out the gas tank and fine tune the air box.

New sprockets
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Clamp on, steering bearings lubed and seated
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Boingers hung
840

Motor and rear suspension bolted up
841

Finally looks like....half a motorcycle lol
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kdxtreme
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Hybrid Gene Splicing

Post by kdxtreme »

you put the hoops on. sweet :supz:
Did I say riding?
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bufftester
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Re: Hybrid Gene Splicing

Post by bufftester »

Yeah, those little buggers were a pain in the ass to weld for me (especially since I just learned to weld so I could do this build), but its not really a KDX without them is it? :lol:

And before anyone asks, yes it is two different colors. I opted for a can of grabber green (about the closest I could find without paying $30 a can) since I want to get riding in the next couple weeks. All the powder coaters around here are running 2 to 3 weeks and want 300 and up to blast and paint the frame. Itll wait
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bufftester
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Hybrid Gene Splicing

Post by bufftester »

Had a good day in the shop, getting close to riding. Down to the little minutia that's slow going...wiring, bits and pieces...

rear tire and brake on
719

Tank modded to clear the head...this was the most stressful part of this build for me, kept thinking I was going to end up with a tank full of holes, it gets soft and gooey quick
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Lots of clearance now
741
728
Carb and air box mounted
782

Subframe bolted up
775

Almost There!
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Last edited by bufftester on 07:03 pm Jul 11 2017, edited 1 time in total.
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Hybrid Gene Splicing

Post by ICRage42 »

that is looking really great! Bet your anxious as all ever. Shoot couple more times in the shop and your done really. For sure keep the updates coming.

Btw.....that grabber green or whatever you used looks really good with the plastics better then frame color :hmm:
If you cant fix it with a hammer, you have an electrical problem.
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Re: Hybrid Gene Splicing

Post by kdxtreme »

bufftester wrote:Yeah, those little buggers were a pain in the ass to weld for me (especially since I just learned to weld so I could do this build), but its not really a KDX without them is it? :lol:

And before anyone asks, yes it is two different colors. I opted for a can of grabber green (about the closest I could find without paying $30 a can) since I want to get riding in the next couple weeks. All the powder coaters around here are running 2 to 3 weeks and want 300 and up to blast and paint the frame. Itll wait
I did the same thing you can't even tell when the bike is all built plus any finish will get beat up over time.
Did I say riding?
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bufftester
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Re: Hybrid Gene Splicing

Post by bufftester »

Well, a late push in the week, and early morning wrenching on Sunday, had the bike finished and ready to ride, which we promptly did 30 minutes later in a local poker run. So literally within an hour of finishing the build, it was in the desert alive! Third kick to start a motor that has sat for 4 years and been rebuilt, these things are indestructable. Last thing done was bleed brakes and test ride, which promptly showed a misadjusted carb float, 15 minutes later that was fixed and 30 mins after that she was off the trailer and playing. Thanks to everyone for their previous work and answering all the questions. I took probably 200 photos during the build, so if there is part you are interested in that isn't on this post let me know.

On a side note, at the ride on Sunday a rider came up to me and asked if I was on KDXRider.net and my name was Bufftester. TUrns out it was our very own kdxtreme! (riding a VERY nice TM450). Cool way to finish the build, thanks for saying hi Dusty.

A few of the final pics. Wiring (I used the KX125 coil, works great)
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The Final Result
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Last edited by bufftester on 07:07 pm Jul 11 2017, edited 1 time in total.
Roadhazardguy
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Re: Hybrid Gene Splicing

Post by Roadhazardguy »

Very nice, it looks awesome! So how's it ride?
Tony
1988 KDX 200
1980 KD 80
1989 ATK 406
1984 RM 500
1980 KZ 1300
2008 SM450R
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bufftester
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Re: Hybrid Gene Splicing

Post by bufftester »

Rides like a dream. have to dial the suspension in still, but it works so much better than the KDX hangers. The stuff we rode yesterday would have beat me to death on the KDX, only beat me half to death on the hybrid :grin:
Bike feels more agile, and even though it sits higher, doesn't feel top heavy, carries the weight well. Odd feeling not being locked into the KDX seating position, found you can actually move around on a bike seat! lol Already looking for the next hybrid donors for my son.
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rbates9
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Hybrid Gene Splicing

Post by rbates9 »

:bravo:
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Hybrid Gene Splicing

Post by kdxtreme »

Cool meeting you out in whoopville :lol: your bike turned out great get that sucker dialed in and take it into the woods your going to love it there. :lol:
Did I say riding?
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bufftester
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Re: Hybrid Gene Splicing

Post by bufftester »

Sixstring,

Yeah that was pretty much it. I cut off the KDX lip behind the flat part that the clamp rides on.and trimmed the little ridge on that end off so it was flat all the way around. I then started trimming off a little bit at a time off the back and test fitting in the KX boot until the KDX one fit all the way back against the inner lip on the KX boot and the front of the two was almost lined up. Then just used the KX clamp over the whole thing. I did put a little permatex gasket seal between the KDX and KX boots to hold it all together. I did find that the easiest way to get it all on is to take the upper shock mount boot out, and unbolt the subframe. Then with the shock out of the way its really easy to line up the boot on the carb, bolt the subframe up, then bolt up the shock. I found that my KX boot lined up nearly perfectly using the stock KDX reed block.
Last edited by bufftester on 07:08 pm Jul 11 2017, edited 1 time in total.
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Re: Hybrid Gene Splicing

Post by Tyl3r »

Hows the carb boot lip adapter been working out for ya? I'm contemplating doing this myself. Any signs of dust or anything sneaking past?
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