Kick a** two strokes!

Inferno
Posts
390
Joined
3/8/2024
Location
Laguna IC
4/4/2025 9:43am
cwtoyota wrote:
Like @SmokinJoe439 said, its a later frame with a current ≈2024 YZ250 engine.  I built a bottom end from new OE parts with all my gearbox...

Like @SmokinJoe439 said, its a later frame with a current ≈2024 YZ250 engine.  I built a bottom end from new OE parts with all my gearbox upgrades, then Jamie at Twisted put a fire breathing top end on it.  Duane (BBR) did all kinds of wizardry to make that frame work with the old bodywork and subframe including the modified shock. 

The swing arm and linkage are from a late model four stroke.  I had the same rear-end setup on my 2010 YZ250 and now on my 2019 model.  I think Doug Dubach was the first one to do that swap, or at least the first to popularize it.

 

Man, you should be proud to have participated in a project like that!!

2
cwtoyota
Posts
2388
Joined
3/11/2013
Location
Tacoma, WA US
4/4/2025 10:08am
cwtoyota wrote:
Like @SmokinJoe439 said, its a later frame with a current ≈2024 YZ250 engine.  I built a bottom end from new OE parts with all my gearbox...

Like @SmokinJoe439 said, its a later frame with a current ≈2024 YZ250 engine.  I built a bottom end from new OE parts with all my gearbox upgrades, then Jamie at Twisted put a fire breathing top end on it.  Duane (BBR) did all kinds of wizardry to make that frame work with the old bodywork and subframe including the modified shock. 

The swing arm and linkage are from a late model four stroke.  I had the same rear-end setup on my 2010 YZ250 and now on my 2019 model.  I think Doug Dubach was the first one to do that swap, or at least the first to popularize it.

 

Inferno wrote:

Man, you should be proud to have participated in a project like that!!

I just had a small part to play, but it was very cool.

3
JMX82
Posts
1573
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Location
Hyllykallio FI
4/10/2025 9:28pm
T500
27
1
PatH
Posts
114
Joined
9/21/2022
Location
That One, PA US
Fantasy
4/11/2025 3:11am
CrGuy2T wrote:
Buddy Antunez factory Primal Impulse race bike restored and for sale. Robertmartin517@yahoo.com if anyone is interested please email..  

Buddy Antunez factory Primal Impulse race bike restored and for sale. Robertmartin517@yahoo.com if anyone is interested please email.. 

 

IMG 2205 2.jpeg?VersionId=89qIMG 2207 4IMG 2192 1IMG 2132 3IMG 2206 3IMG 2209 2.jpeg?VersionId=DMsE QaHUT4clX2Xo97yUg0RU11A5kU

Cool build, swing arm nut is either too loose or the bolt isn’t long enough.  

The Shop

evomx244
Posts
237
Joined
1/19/2008
Location
Morrow, OH US
4/11/2025 4:10am
alphado wrote:
[img]https://p.vitalmx.com/styles/s1200/s3/photos/inline/basic/IMG_8307.jpeg?VersionId=KvKoozC5IjjbXCBlET5o1iflMn8Q5qjI&itok=52SqqHTl[/img]

2004 ?

alphado
Posts
4055
Joined
8/15/2006
Location
Erie, PA US
4/11/2025 4:46am

Yes, 2004.

jjsmooth
Posts
25
Joined
12/31/2006
Location
Cincinnati, OH US
4/13/2025 11:19am
IMG 20250411 115712
8
jjsmooth
Posts
25
Joined
12/31/2006
Location
Cincinnati, OH US
4/18/2025 8:49am

The '78 KX250 is for sale if anyone interested.

1
evomx244
Posts
237
Joined
1/19/2008
Location
Morrow, OH US
4/24/2025 4:43am

My 1996 KX250, upgraded with 97 Swingarm. easily one of my favorite bikes I owned. I sold it to a friend 10 years ago, instantly regretted selling. I was finally able to buy it this past weekend. Luckily, he hardly rode it and changed nothing on it. s1200 image 5

11
mxaniac
Posts
533
Joined
9/9/2019
Location
Airway Heights, WA US
4/25/2025 8:25pm

The KX500AF melted in a fire. I just sold the Husky because I preferred the Honda. 

20241013 151634 0.jpg?VersionId=p7JQJdWPSV 3EjmzM4H. z33B

 

20240620 120650 0

 

1jm6o1
3
4/25/2025 8:39pm
mxaniac wrote:
The KX500AF melted in a fire. I just sold the Husky because I preferred the Honda.   

The KX500AF melted in a fire. I just sold the Husky because I preferred the Honda. 

20241013 151634 0.jpg?VersionId=p7JQJdWPSV 3EjmzM4H. z33B

 

20240620 120650 0

 

1jm6o1

Nice , i  know what your talking about . Recently I Really wanted to go home just to b with my bike but it’s too dam cold.  What front rotor ?  Crf stuff co ?  And the rear ? 

3
MX707#
Posts
130
Joined
2/2/2022
Location
Charlton City, MA US
4/26/2025 5:14am

Been loving this 02 cr250, such great bikes for being how old they are

1000009747 01000009748

 

5
4/26/2025 5:39am
MX707# wrote:
Been loving this 02 cr250, such great bikes for being how old they are  

Been loving this 02 cr250, such great bikes for being how old they are

1000009747 01000009748

 

Looks Awesome and rides like a dream.  I check out bike builds just to see them down to the frame , soo Hot. Then u put all the sexy parts on and Wow just soo Awesone lookin . Then u ride them and the feeling & feed back from the bike is perfect .  The 02 is Super popular guys that hv built 450,s r more excited to show there 02 off.  I think there wayy bigger now than in 02.  Just like my 04 every time at the track all kinds of people come ovr asking what yr is it.  Being the rare 04 they freak . I say way till u here this thing. It sounds like a Tom Kat with rabies that was thrown onto a power line. That just finished ripping a junk yard dogs head off. 

1
-MAVERICK-
Posts
65640
Joined
3/26/2015
Location
Ontario CA
4/26/2025 9:29am

Jared Lesher's 1983 Broc Glover Throwback for Pittsburgh.

1000007057.png?VersionId=Hb6X7SRl2vxyDkQNiuZmqeXwB.1000007056.jpg?VersionId=9CnyOyc1DUjBWi3gpggg
19
2
4/28/2025 9:36am
IMG 0421 1IMG 0420 4.jpeg?VersionId=h2QEvtGz6I2vjMZh29WsVEHAF6IMG 0419 1.jpeg?VersionId=kzVJiktS.vRkbq

On this build they have a Pro Circuit shifter on the bike. Pro circuit does not list one for the 2-stroke KX250 on their website I want one for a build, I reached out to BYD and the builder with no reply back. Does anyone know which shifter they are possibly using that works on the 2-stroke KX250? Any help is greatly appreciated. 


 

4/28/2025 9:49am
IMG 0421 1IMG 0420 4.jpeg?VersionId=h2QEvtGz6I2vjMZh29WsVEHAF6IMG 0419 1.jpeg?VersionId=kzVJiktS.vRkbq
On this build they have a Pro Circuit shifter on the bike. Pro circuit does not list one for the 2-stroke KX250 on their website I...

On this build they have a Pro Circuit shifter on the bike. Pro circuit does not list one for the 2-stroke KX250 on their website I want one for a build, I reached out to BYD and the builder with no reply back. Does anyone know which shifter they are possibly using that works on the 2-stroke KX250? Any help is greatly appreciated. 


 

I would try cross referencing some other after market shifters to see if a 250f one fits a two stroke model and start there. It may have been one they just happened to find somewhere. I know pro circuit only builds them for certain models for just so long.

2
cwtoyota
Posts
2388
Joined
3/11/2013
Location
Tacoma, WA US
4/28/2025 11:49am
IMG 0421 1IMG 0420 4.jpeg?VersionId=h2QEvtGz6I2vjMZh29WsVEHAF6IMG 0419 1.jpeg?VersionId=kzVJiktS.vRkbq
On this build they have a Pro Circuit shifter on the bike. Pro circuit does not list one for the 2-stroke KX250 on their website I...

On this build they have a Pro Circuit shifter on the bike. Pro circuit does not list one for the 2-stroke KX250 on their website I want one for a build, I reached out to BYD and the builder with no reply back. Does anyone know which shifter they are possibly using that works on the 2-stroke KX250? Any help is greatly appreciated. 


 

Lots of different brands use the same standard spline.
For example, a YZ250 shifter would fit my 1990 KX500 original shift-shaft and actually fits the bike as well.

I upgraded that shift shaft to the later (larger splined diameter) part which started in 1997 or 1994 (I don't remember which year).
The KX500 and KX450F shifter lever are similar and the splines are the same for that larger shaft.
I would imagine the KX250 two stroke also has that larger spline diameter and I believe the YZ450F models share that also.

That opens up some potential options, but for the shape of the shifter lever, I can't help you... 
You'll just have to look at some bike photos to come up with possible candidates and then find out the spline counts.
You can order a cheap Tusk shifter to confirm fitment before you spend the big bucks on a nice PC part.

4/29/2025 1:58pm
On this build they have a Pro Circuit shifter on the bike. Pro circuit does not list one for the 2-stroke KX250 on their website I...

On this build they have a Pro Circuit shifter on the bike. Pro circuit does not list one for the 2-stroke KX250 on their website I want one for a build, I reached out to BYD and the builder with no reply back. Does anyone know which shifter they are possibly using that works on the 2-stroke KX250? Any help is greatly appreciated. 


 

PM.

1
bonseff
Posts
1996
Joined
3/29/2011
Location
Frisco, TX US
5/22/2025 8:52am

May be an image of motorcycle
 

5
5/22/2025 10:22am
Is it just me, or is there something that the new bikes lack in "cool" factor? Bikes like these sure used to get me excited......and they...
Is it just me, or is there something that the new bikes lack in "cool" factor? Bikes like these sure used to get me excited......and they still do today 10yrs later.Cool

Who makes or sells the red radiator hose wrap on the hose inside the pipe ?   

2
5/22/2025 5:48pm
Is it just me, or is there something that the new bikes lack in "cool" factor? Bikes like these sure used to get me excited......and they...
Is it just me, or is there something that the new bikes lack in "cool" factor? Bikes like these sure used to get me excited......and they still do today 10yrs later.Cool

Who makes or sells the red radiator hose wrap on the hose inside the pipe ?   

It's silicone coated fibreglass, commonly called fire sleeve.

Made by many companies, if you are only after a small quantity, ebay is your best source...

https://www.ebay.com/itm/205012945123

1
JWACK
Posts
2562
Joined
8/7/2009
Location
NM US
6/6/2025 10:22am
IMG 2113 6
12
JWACK
Posts
2562
Joined
8/7/2009
Location
NM US
6/7/2025 3:13pm
IMG 2134
5
mtb133
Posts
29
Joined
1/5/2022
Location
Erie, PA US
6/7/2025 8:21pm Edited Date/Time 6/7/2025 8:23pm

2022 RMZ250 chassis 2007 RM250 enginePXL 20250427 211639500 1.jpg?VersionId=SEmOp1.OewpC

15
6/18/2025 5:24am
mtb133 wrote:
2022 RMZ250 chassis 2007 RM250 engine

2022 RMZ250 chassis 2007 RM250 enginePXL 20250427 211639500 1.jpg?VersionId=SEmOp1.OewpC

It seems that the silencer is very low, do you think it will not be in contact with the rear brake caliper?

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