Author Topic: 2003 KX125 with 2006 YZ250F SSS forks  (Read 7404 times)

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Offline kenpowell

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2003 KX125 with 2006 YZ250F SSS forks
« on: July 01, 2014, 05:44:32 AM »
I'm new to the forum but I have been wrenching / riding since 1970.  I'm building a 2003 KX125 / KDX200 hybrid and I'm using 2004 YZ250 triple clamps, a YZ250F stem, and 2006 YZ250F SSS forks.  Everything is bolted up properly but I have no idea of the correct fork length since I do not have the KX125 forks.  Can someone provide me with the length from the center of the axle to the bottom of the lower triple clamps?  If I have this length I can shorten the forks to the correct length; heck, maybe I'll get lucky and not changes will be necessary!
Ken Powell,  Bryant,  AR
kenpowellatcomcast.net

Offline KXDINO

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Re: 2003 KX125 with 2006 YZ250F SSS forks
« Reply #1 on: July 01, 2014, 09:04:08 AM »
Here a few numbers to chew on ,kx125 04 to 08 ,should be the same as a 03 ?centre of axle to top of fork cap is 940mm, centre of axle to bottom of clamp is 672 mm ,bottom of clamp to top of clamp is 265mm the yz could have different clamp sizes plus the fork on this bike is set at bottom of top cap is flush with top of clamp ,hope this helps.Let us know how these fork work on this bike .

Offline KXDINO

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Re: 2003 KX125 with 2006 YZ250F SSS forks
« Reply #2 on: July 01, 2014, 09:26:09 AM »
Another thing is to how does the off set of the yami clamps compare to the kx ones I think the kx ones are 25mm not 100% sure does any one know what the yami is ,they change this a bit over the years unless you keep a record of it all,off set changes the trail and can alter the handling of the bike ,so keep this in mind.Can you give me the measurement of the forks of the sss were the clamps go ,most kyb are 59mm on the bottom ,it the top that different I think the yz were 56mm the kx 125 08 were 55mm you could machine the top clamp to 56 easy as there is plenty of meat in that area especially on the early kx 01 era they were thick there just a bit of info in case any one wants to change forks.

Offline kenpowell

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Re: 2003 KX125 with 2006 YZ250F SSS forks
« Reply #3 on: July 01, 2014, 11:28:45 AM »
The triple clamp offset on the YZ (up thru 2011?) is 25mm, which should be the same as the '03 thru '05 KX125.  I think I'm OK there.  Thanks for the numbers; that should be what I need.  I'll get back with how the forks work.  I'm still about 3 weeks away from riding.

Offline kenpowell

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Re: 2003 KX125 with 2006 YZ250F SSS forks
« Reply #4 on: July 01, 2014, 02:14:38 PM »
I used '04 YZ250 triple clamps (25mm offset) with a '08 YZ250F stem.  Since everything is 'YZ' it all bolted together with no problems.  The triple clamps needed a 3mm spacer on the bottom of the stem under the lower bearing to get the bearings to seat into the KX steering head.  Note that the KX and the YZ use the same steering head bearings so it is only a matter of matching up the correct stem and spacers.  I used a '03 KX125 front wheel and brake and turned the KX spacers down on my lathe to get the correct fit of the front wheel.  The front caliper bolted right up.  I also used a '08 YZ250F front brake hose to get the 'new' brake hose routing.  Lastly, the axle clamp offset on the YZ SSS forks is 30mm which I think was also used by Kawasaki.  This should keep trail the same if I can match the measurements that you provided.

Offline sandblaster

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Re: 2003 KX125 with 2006 YZ250F SSS forks
« Reply #5 on: July 01, 2014, 04:11:53 PM »
Pics?
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline KXDINO

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Re: 2003 KX125 with 2006 YZ250F SSS forks
« Reply #6 on: July 01, 2014, 04:26:15 PM »
Good stuff Ken.

Offline kenpowell

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Re: 2003 KX125 with 2006 YZ250F SSS forks
« Reply #7 on: July 02, 2014, 01:06:00 AM »
No pictures at this time.  I'll get some this weekend when I work on the bike (after my Saturday ride, of course).

Offline kenpowell

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Re: 2003 KX125 with 2006 YZ250F SSS forks
« Reply #8 on: July 15, 2014, 04:04:12 AM »
I'm getting close...  Still need to install the chain, finish the wiring, and find the correct throttle cable to go with the new PWK35AS (with the regular PWK throttle cable adjuster).  Pictures are here:  http://s34.photobucket.com/user/ken-powell/library/?view=recent&page=1

Offline sandblaster

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Re: 2003 KX125 with 2006 YZ250F SSS forks
« Reply #9 on: July 15, 2014, 05:26:52 AM »
That is nice and clean.
Good job.
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline kenpowell

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Re: 2003 KX125 with 2006 YZ250F SSS forks
« Reply #10 on: August 01, 2014, 02:01:22 AM »
The bike is now finished - 2003 KX125 with 1996 KDX200 engine. It weighs 221 lbs with all fluids but no gas. The bike is woods ready - bark busters, skid plate, rear rotor guard, rad guards, heavy duty tubes front and rear & new tires.  Here is the link to pictures:

http://s34.photobucket.com/user/ken-powell/library/?view=recent&page=1



« Last Edit: August 01, 2014, 03:52:58 AM by sandblaster »

Offline kenpowell

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Re: 2003 KX125 with 2006 YZ250F SSS forks
« Reply #11 on: August 05, 2014, 01:48:21 AM »
Update - I am now riding the bike and the handling/steering is perfect with no bad habits.  The axle lug offset must be the same between the '06 YZ forks that I am using and the original KX forks (which I don't have).  Feels very much like my YZ265WR bike  - of course it feels much lighter even though there is only about 12 lbs difference.  I am really impressed at how well the bike holds a line and how precise you can be when choosing a line.  It feels a little down on power but that is only because I am used to a YZ265WR and a '12 KTM 300 XC.  I have to many motorcycles and something has to go - but it won't be this little beauty.  Pictures:  http://s34.photobucket.com/user/ken-powell/library/?view=recent&page=1

Offline Foxx4Beaver

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Re: 2003 KX125 with 2006 YZ250F SSS forks
« Reply #12 on: August 05, 2014, 07:36:42 AM »
love it!...that is one sharp lookin build.
Excuse me, ma'am...but you've got extremely nice legs!!!...what time do they open???                                                                                                               https://www.youtube.com/watch?v=n8tCgN3aryQ