Another damn KDX/KX hybrid......

[Biggles]

Yes another thread on a hybrid build thread, but thought I might do a project report from a man with a young family and restricted budget perspective. I say restricted budget, but aim not to compromise on quality and to show if you search for the right parts the total spend can be kept down. I have also set a six month timeframe as I have a second child due in 4 months and am studying after work.

Heres what I have ready to start:
HRDRKN's PDF file
S/H 2003 KX 125 complete less motor
S/H 1996 KDX 200 motor
New FMF Pipe
Works Con frame guards picked up on a clearance table
New 08 450 Rad Shrouds that someone had in their shed
New 11 YZ 125 Muffler - never used and at a price I couldn't refuse

Spend to date - $940 NZD

Apart from bearings/tyres and brake pads I think I have everything I need. I work for a machine shop and the boys ride so their keen to start on the swingarm/motor tomorrow. Will post some pictures soon.

 

[Biggles]

Month 1 - Project Start

Aim for month - have swingarm machined and back of motor drilled to accept larger swingarm bolt. Have a few pictures so need to brush up on how load them. Also found a steering stabiliser I forgot I had in bottom of cupboard, will get post welded to frame when I redo engine mounts.

 

[mudpack]

Sounds like a lot of mismatched parts trying to become someone's headache.
If you get all those pieces to work in concert, you'll get my award as Masochist Of The Year.
I wish you the best of luck, though, and hope you are successful.

 

[Biggles]

Update 2

Motor, swingarm and bushes machined. Even had a new swingarm bolt made. Will take home tonight and start on motor fitment in a week or two after exams finished.

 

[Biggles]

Hey mudpack - if all goes to plan should be ok. Swingarm machined and motor mounts cut so no turning back now.

 

[Okiewan]

Good luck! Keep us up to date!

 

[Biggles]

Update 3

Needed a break from study. Motor in frame - no clearance issues with tank. FMF pipe fits with no clearance issues either, so far so good. In process of getting new rear headstay bracket fabricated so motor sits where I need it to have lower engine mounts welded up. It all seems like a 03 125 frame was nearly made to take a 200 motor. Back shock in for a service and fatboy spring.... :yikes:

On a side note - on the way to pick up YZ muffler had a change of mind and ordered a new KDX 200 FMF jobby instead. Added a hundred to the bill but will probably save that amount in fab costs :whoa:

After a bit of research, I am looking at getting a nylon ring made to help mate the carb to the KX airboot instead of mounting a KDX airboot or just tightening the crap out of the KX airboot. Hopefully this will create a good seal, time will tell.

 

[cbrslider]

Very interesting. Keep the info coming. It's nice to see the progress. Good luck.

Ray

 

[Biggles]

Quick update (but no photos)

Shock serviced and another spring - turns out a YZF spring is the same dimensions but 10mm longer and picked one up for $50 in the right weight range so will give it a try. Top head stay just being welded up now so will be able to get to the bottom engine mounts shortly. Spend to date $1285

 

[Biggles]

Update 5

Not much happened since last update - exams next week and assignments due :think:. Headstay finished which means motor sitting in frame ready for the bottom engine mounts to be welded in. Hopefully will get back to it in two weeks :fft:

 

[Biggles]

Update 6

Not much happening - between flat out with study and work no spare time. New bottom engine mounts cut and ready to be welded but workshop is flat out and the guy I want to weld them is on holidays for two weeks :( All parts except for plastics has been ordered and had to get new front spokes as the spoke/nipple relationship was to tight to break. Cost to date $1700NZD and all thats left is a fork rebuild/springs and plastics when I decide on colour so should finish up around $2K

 

[Biggles]

Update 7

Managed to get out late last night and look at the pipe. Bottom of muffler starts where the 125 one started so should be no clearance issues. Need to weld new tab at top and shortened bottom muffler mount and weld new tab on subframe. The muffler to header out by about an inch so a bit of cut and shut needed. Haven't cut anything yet so if anyone has other ideas please pass them on. I am trying to get the pipe to sit roughly where the stock 125 was and poke out the top a bit more.

Nearly decided on colour, think I will go close to std and have 200SR instead of KX125 and see if anyone notices :laugh: :laugh:

 

[Biggles]

Wheels laced up and at shop to get trued and tyres put back on. Caught up with the guy I want to weld the mounts this week so should be ready to put all together to make sure everything fits before pulling back down for powdercoat soon. Also need to get forks done. Fingers crossed I will have a picture of a complete bike in the next week or two :nod:

 

[Biggles]

Update 8

My apologies for the boring updates - frame welded at last. Time to start piecing back together to ensure everything fits before paint. Have decided to weld mounts for a skid plate and water pump guard on so a little more welding but should be worth it in the long run.

 

[BSWIFT]

You've really done a great job documenting your build. From my 2D view the build looks real good. The 200KX conversion is something I would like to do but have not located reasonbly priced donors.

 

[Biggles]

Small update

Wheels back, now I know I should have bought a new rim (one was black and one was silver when I picked the bike up) but the new rim was $200+ and powdercoating was $100 for both. My riding ability and wallet determined pc will do :yikes:

BSWIFT - I have been planning this for 3 or so years (well talking about it) before I found the parts at the right price. I was looking for a low maint/low cost fun bike and love my 200 2 strokes. I couldn't justify $10K+ for new one

 

[Biggles]

Update 9

Bad day at work so spent some time in the shed. I'm using an 03 frame with the one rear headstay. Front headstay mount on the head rubs on the bottom rad hose. No prob as this was going to be milled off anyway but something to be aware of. KX125 bottom rad hose to waterpump too short so will get a KDX one and should be ok. Coil mount a tight fit so will have a think about that. So far these are the only small problems I have come across.

 

[Biggles]

Tank clearence

Room here so no heating/bending tank.

 

[Biggles]

Update 9 cont

Started putting back together to check fitment.

 

[HRDROKN]

Looking good!!!

:cool:

 

[Biggles]

Expensive lesson

When I started the project Ithought I was smart by purchasing a full KDX200 exhaust, dumb move. Tried to heat and bend pipe to line up with expansion chamber. Result - 1 not so good muffler. Fix, $200 later and purchased a new KX 250 FMF silencer. Nearly lines up, just need to move mount on subframe and look at how to bridge the inch short join on the silencer to expansion chamber. It overlaps by 3/4 inch but I'm worried about the seal.

On a better note, forks should be back soon, coil and exhaust mounts to be welded early next week :)

 

[Biggles]

Yeah progress.....

Progress made on pipe at last. Note to anyone thinking of this a KX 250 muffler is the easiest option if you use a 03 on 125 frame. Managed to sell 200 muffler for half price so not all is lost. Coil mounts welded, top muffler mount welded and muffler mount on sub-frame welded. Taking into workshop tomorrow and getting them to lengthen expansion chamber to match muffler. Weld will be behind the frame rail near footpeg so shouldn't see it.

Only decision left, do I put KX numberboards on it or a headlight and tail light like a KDX???? I'm leaning toward headlight as I prefer the enduro look...Thoughts anyone :think:

 

[Biggles]

Update 9

Finally, all welds and muffler mounting complete. Time to tear down and get ready to powdercoat/paint. Still haven't decided on colour/graphics but damn there's a few people out there that advertise a lot of product for people - Monster/Rockstar etc. I may be old school, but if they don't give you something why advertise???? :coocoo:

 

[Biggles]

Carb mod

Guys in the workshop finished carb ring today. They machined rear rim off carb, made an 1.5mm aluminium rind .25mm to small, heated and slide over carb intake. Once cooled we have a tight fit. Aluminium ring has a lip on back face like standard carb for airboot to grip. This way I can use the standard KX airbox and boot. :ride:

Only welds for water pump guard bracket left to do then powdercoating and final assembly. :nod:

 

[Biggles]

Frame finished

Frame finished, a bit lighter than expected but for a beer payment will be all good. Only hold up now is a stuffed knee from soccer so will be stored in shed for a few months :yell: But hey, at least evrything is there for reassemble :cool: