01 Mike Brown replica build Kx125

jowek70
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austin, TX, USA

Picked up an 01 kx125 a few weeks ago and doing a full rebuild/replica build.  Frame and hard parts are at the powder coater, sourcing pro circuit parts, ordering parts, etc. 
So far, have calipers, master cylinders rebuilt, wheel bearings and swingarm bearings replaced, carb rebuilt and a ton of parts in boxes yet.  

I am doing a Mike Brown PC inspired build, staying as period correct as possible.

Here is the bike when i picked it up, $350 minus the engine and pipe.  It came with a top end and R304 silencer, picked up a bottom end and brand new pipe for $650.

IMG 3172

 

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jowek70
Posts
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Joined
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Location
austin, TX, USA
2/9/2023 2:25pm

Relevant info:

Bike came with a White brothers upper triple clamp and some aftermarket pegs and rear sprocket, all in useable shape.

Going stock bore on the cylinder for now, its in great shape at 54mm.

Will be doing kawasaki green powder and plastics instead of the flo green as the graphics manufacturer can't do flo green

i'll be running my old race number, 70, instead of Mikes #100 and i'm going to be riding this bike at local tracks on the weekends and a few old man races with my friends.

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2/10/2023 7:11am

Best of luck. I finished off a similar build last year myself. I think the most difficult thing would be finding certain parts, granted your project bike looks like it was maintained better than where I started. Good luck with your build!

 

s1200 20210709 172658 HDR

 

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jowek70
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2/10/2023 7:28am Edited Date/Time 2/10/2023 7:28am

Bike looks great, nice job!

I'm only doing an aesthetic replica build, haha, most of the PC parts are rare and expensive nowadays. 

Got some parts back from powder, here's a pic of the rims.

 

Rim 0

 

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2/10/2023 4:16pm

Clean bike. Before you drop the low end in it. Watch Gary baily channel unadilla& washougul great vid of Brown’s bike ripping. It sounds so Good . Then you’ll want to get the cases stuffed & porting.  Denmark had 4 non ama races last yr. It’s a euro layout now but has really fun floater jumps 1 hill has 4 lanes

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The Shop

jowek70
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austin, TX, USA
2/13/2023 6:29am

Do you know any good shops? i've used US chrome and millenium technologies for cylinder work but not sure who to use for porting

 

2/13/2023 7:48am

Millennium technologies plating is by far the best. They chamfered the ports perfectly too. If you talk to them they know the schedule of TMR since there kinda of in the same building or near each other. Tmr always gets good hp out of an engine. He does a lot engines for older bikes that r tested on here.   JM Racing built Chad Johnson,s 98,99 team green kx125&250. In 98 at byron nuclear race he pulled my 97 Noleen 125 easily. At a pro am at Denmark in 99 his bike had a whicked sound. Quick response with a long & strong mid into the ovr rev. JM racing did a couple 04 cr125,s for me. The 1st bike was stolen.  The 2nd cylinder is amazing I can’t waiting to ride it,8-9 hp ovr stock . They run like national engines quick response with a long & strong mid into the ovr rev. Chad,s 125 sounded the same Really gnarly mid range bark into the top. Not sure what changed from 99 to 01 on a kx. But if there isn’t much get Chad,s spec from 99. I got Tara Gieger,s replica LL championship spec with a bit more torque since I ,m a little bigger than a chic.  I knew an ignition wasn’t available for a 04 like my 05. But John,s porting work is so Amazing that I had him do my 04. 

jowek70
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2/14/2023 4:16am

After inspecting the cylinder, i'm going to use as-is.  Its in fantastic shape and will just need to gap the ring and install and engine will be ready to go.

Waiting on powder yet, my guy is on vacation til next week unfortunately but will have everything ready to start reassembly.  Going with Bridgestone tires to stay period correct and dropping suspension off to get resprung/serviced next week as well.

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jowek70
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2/15/2023 7:22am

Ordered last of engine parts today.  Dropping by ACE for some stainless steel metric hardware and some minor sub-assembly tonight.

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2/18/2023 12:14pm

JM racing porting should give you a strong& long mid into the ovr rev. Will make it easier to ride short shift or rev it out. Will sound Great too.  Here is Denmark Mx schedule 200 to join 2 tracks + a kids track. You can bring a guest to ride. 6F2743C5-0A0F-4309-9669-1BFDB58C3523

 

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jowek70
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2/20/2023 6:10am

do they run open practices? i haven't swung a leg over a dirtbike since high school haha.  Will definitely need some track time before competing.

2/20/2023 4:09pm

Race day has a short practice. After the race there’s open practice until 8pm.  Web for info rpaoffroad.com he,s changing a a lot of stuff. Denmark was a ama track 1969 to 2015. Its not a ama track now. I was a member 1991 until 2013.  2nd race in 22 got a 50+ class. I see the 125 class is 150 now.  I checked out the 1st race a couple riders on 125,s said it has a great flow for 125,s. Race day is super chill the 125 class had mostly older bikes. Mon track is closed teus- sat open til 8pm, sun I forgot it’s 1 or 3 pm. 

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jowek70
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2/21/2023 9:53am

Thanks for the info, definitely have to look for you in the pits.

1
2/23/2023 7:57am

0441B0DB-386B-4CAE-A2F9-20F47AB53C48.jpeg?VersionId=CdEisFondI hope so depending on how my back or neck surgery goes. I had 2 apt & 2 diff dr,s checking out a large tumor ovr a spine back muscle below my shoulder blades . Mon at 2 I had it removed in the storm. It didn’t go very well. It was supposed to b a floater on top of the muscle but it’s into & below the muscle. I had 2 more injections to numb it. A lot of cutting etc . Can’t bend or lift anything or any kind of exercise. It took 1.5 hrs of cutting & 4 people 2 where cutting the 3rd trying to move the tumor to cut it off the back muscle. Yeah it turned into a nightmare. I thought it was going to b a piece of cake, in& out in 20 min. Pic of the up hill start. Could b the only 1 in the world.

 

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jowek70
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2/23/2023 10:47am

cool pic, sorry to hear about the surgery issues, heal up and keep safe!

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2/25/2023 11:31am

Yeah Thx. My Dr called with the mri results. It sounds bad .Long story but it sounds like no surgery because it would make things worse.  3-6 I see a specialist then doing injections . 

jowek70
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2/27/2023 5:42am

sorry to hear man, good luck with everything.

jowek70
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2/27/2023 5:47am

started on the engine last night; need a few things yet but going very well.  Top end kit dropped right in and has great compression!

I was able to media blast the top end but not the bottom end yet.  Pick up a works bolt kit and fancy oil fill and drain plugs.  New spark plug, and painted the stator cover.  Clutch and KIPS cover getting same paint as well to mimic the PC cover colors.  

IMG 3270IMG 3269.jpg?VersionId=ZhE2M4zl44dCLEF4sh5dSDKxLS

 

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2/27/2023 8:18am

Looks Great. I had my 05 complete engine vaper blasted. When I got it back I put it in a tote box. While I completely disassembled 2 04,s. Then I go to install the 05 & the crank wouldn’t move . It was rusted tight from the water in the vapor blasting. I used 3/4 of a can of pb blaster. I got it to move. It started 1st kick huge smoke cloud filled the area . The crank bearings are making a grinding sound. I hv to buy a oem new crank or rebuild the hot rods crank. 

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jowek70
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2/28/2023 11:00am

Ordered a new clutch today and a few odds and ends.

One of my radiators lost the inlet pipe, going to see if a local shop can reweld for me, if not, probably have to go searching.

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jowek70
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3/1/2023 6:38am

IMG 3271.jpg?VersionId=BJvNidIBnQ7

 

Got all the parts, just waiting on frame and stuff from powder coating to get this build finished up.  Waiting on graphics kit from overseas.

 

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jowek70
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3/7/2023 1:14pm

Picking up powder parts tonight, ordered tires and picked up final parts this past weekend. Few more things to order yet, but should be starting reassembly tomorrow.

Pics to come.

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jowek70
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3/8/2023 7:45pm

C3F13BBC-37BE-4D3B-84C6-8305FA4A7514

 

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jowek70
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3/8/2023 7:46pm

2ED7EFE5-7F91-439F-ACC5-45D9C11C4EA1.jpeg?VersionId=lgAZqLVbp.E56ZHZXSRfUlAAMk80f0

 

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jowek70
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3/8/2023 7:46pm

EFA7DE23-8197-4DEE-9262-01A78E088C52

 

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jowek70
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3/8/2023 7:47pm

Progress!

jowek70
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austin, TX, USA
3/13/2023 5:22am

Got a bunch done this weekend; spinning tires on tomorrow and should have suspension back in 2-3 weeks. 

Almost there!

Hoping by the time I get my suspension back the weather has stabilized so i can tune the carb and start turning laps.IMG 3292.jpg?VersionId=0Lm1oE0JFZ

 

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jowek70
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3/13/2023 4:06pm

BB426ABA-E62A-45BA-905A-2819469C4A4D

 09E2FB2C-033D-4437-8EED-B3B3DADF23B7.jpeg?VersionId= UbG8CXOd6qerHSF.L

 F67F2BCF-E7A8-4F4A-A375-C2E77793DC54

 

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jowek70
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111
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Location
austin, TX, USA
3/17/2023 6:23am

Tires on!

waiting on suspension now.

Woke up to some snow this morning and another couple days of chill yet, so have a few weeks to get the rest of this put together and tuned; shooting for an open track day on saturday 4/29.IMG 3302.jpg?VersionId=EI UJVuBN

 IMG 3303

 

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3/17/2023 11:37am
jowek70 wrote:
Tires on! waiting on suspension now. Woke up to some snow this morning and another couple days of chill yet, so have a few weeks to...

Tires on!

waiting on suspension now.

Woke up to some snow this morning and another couple days of chill yet, so have a few weeks to get the rest of this put together and tuned; shooting for an open track day on saturday 4/29.IMG 3302.jpg?VersionId=EI UJVuBN

 IMG 3303

 

The frame& plastic look so cool& bright. Yeah the weather is horrible yet. Sunday night the snow& wind was crazy. Today it’s 9 with the wind chill.  The wind goes right threw ya. 

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jowek70
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Location
austin, TX, USA
3/20/2023 3:08am

C6BF3AFC-540B-419D-BC18-B05E0FC2782B

Got her running last night.  Nice and crisp!  Can’t wait to ride it.  Started mounting plastics and mocking things up to ensure fitment .

left hand radiator leaks so waiting on a new one.  Suspension and graphics in the works.

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