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kx 100

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hello everyone! ned a little bit of expertise on this,

so my younger sister (12 yrs and around 5'6) has suddenly gained an interest in riding with me in the summer. so i thought i would get a bike for her that needed some work and make it like new for her in the summer so she can ride the local trails with me. the only problem is that she has a "lets not think, go go go" type of personality and to add to that with her height, i cant get a little 65 for her to ride the trails with. too small.

so i found a really great deal on a kx100 and i was wondering if there is any way to retard the power from that machine. the first time i rode a 2t 85 i was petrified of the power even tho i ride a yfz 450. so is there a way? i think this would be a good bike for her to learn SLOWLY on and will be a fun bike when she gets the hang of it.

let me know!

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Good bikes.I added a 10 oz flywheel weight to the one we had. Tamed the hit and it allowed it lug around better with out stalling. Still had plenty of power.

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My 12 year old son came off a CRF80, to a brand new 06 KX100 rode that for almost 2 years.. We did add a FFW and pipe to it, in order to make it more trail friendly. Worked very well the whole time, trail and MX track the last year without the FFW and a different pipe.

Oh, and what an Awesome big Brother (sister?) you are for doing this...:busted:

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The FWW will definately take it down. Then make sure you go to the Kawi 2 stroke section and look at the FAQ section before anything. There are a few great threads in there regarding the 85/100's.

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the first time i rode a 2t 85 i was petrified of the power even tho i ride a yfz 450.

Do you know why 85s are terrifying to adults, but not to kids? Because your height and weight combined with the very short wheelbase raises the center of gravity to ridiculous heights. That's why "dad" always loops junior's 85 in the back yard when teaching him how to ride it...:busted:

From your post, your sister is the perfect size for the 100. After a little seat time she'll adapt quite nicely.

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That's why "dad" always loops junior's 85 in the back yard when teaching him how to ride it...:busted:

I'm gonna base this on "someones" personal experience, not knowledge of basic physics...

:busted::lol::bonk::lol::lol::lol:

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Just and idea and my opinion.The KX100 is a full bore race bike. The right kid on one can turn lap times that would embarass many experts riding new CRF450s

No matter what you do to a KX100 it will be a KX100

A little girl finding our sport and wanting to ride is priceless. You cant make someone like what we like.If she does not have the disposition for a KX.What if you found a XR80/100 for 500.00 and let her ride the KX next season? You will most likely still be able to sell the XR for what you paid for it or close.She will not become discoraged trying to keep the KX on the pipe while just poking around.Just and idea. I know its not easy to come up with another 5-7 hundred theses days.

I saw someone liked the heavy flywheel on the bike. I rode my friends wifes KX85 with a flywheel. My opinion of it was that it made it a bog machine,Once it feel off the pipe it took forever to get back on.

But if my daughter came to me to ride Id spend alot more than that to keep her interest.

And you are a good guy for doing this for her too.

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KX100, not an 85...

KX100 makes a great trail machine with a FFW, correct jetting and pipe.. Proven thousands of times all over the country.

KX100 is / can be tuned to be a top competitor machine in the rights hands; it is just as easily ridden on fire roads, fields, or single-track trail by an average rider.

At the same time, if an XR100 is available in good running condition, and the riding conditions are very mild.. thats a great starter bike

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washers in the exhaust pipe are a cheap fix for that

I don't suggest this on a powervalve bike. Great for a 65 or a bike with no PV, but not-so-good for those with.

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Look yall, you want the ultimate docile kx100? I have spent some time figuring this out, my grandma could ride mine. Here's what I did:

Heaviest Stealy FWW.

If there was only one mod I could do to a kx100 for trailabilty, it would be the the JMS powervalve, it doubled the off-idle torque and gave the bike a litte soft spot right before a top-end hit, this annoyed me a little at first, but then I relized it is realy nice indicator of what's coming and you can then short shift or back off the throttle to avoid it. The top end may have lost a smidge, but area under the curve is much bigger.

I think the JMS PV fixed in the low rpm position (disconected linkage) and FWW would be a super sweet newby girl bike.

The ultimate can't be bought, but l built an auto-clutch for mine and it is the bomb for easy ridin!

Last thing is do a 12-54 tooth sprocket combo, allows you to go slow!

Edited by TurboStew

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Oh yea, need to go to the next largest carb slide (or grind a mm off the stock one), and go to the leanest option needle from kawasaki, this will make it putt around like a Honda scooter, instead of that fat surgy, sputtery cruise. Second from the top clip position I think. I did the dual stage Boysen reeds, not sure it made much difference.

BTW, mine is street legal!

Edited by TurboStew

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If there was only one mod I could do to a kx100 for trailabilty, it would be the the JMS powervalve, it doubled the off-idle torque and gave the bike a litte soft spot right before a top-end hit, this annoyed me a little at first, but then I relized it is realy nice indicator of what's coming and you can then short shift or back off the throttle to avoid it. The top end may have lost a smidge, but area under the curve is much bigger.

Interested in Sapper's thoughts on this. Is it possible the hole in the torque curve might be filled in by opening the power valve a little sooner? Or is the JMS powervalve set up for low end to such an extent that it just can't bridge to where the pipe starts working?

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That's exactly what is happening. The "hole" is due to the effectivness of the PV shifting the torque curve down so that it goes "flat" before it switches then hang on:) I verified this by removing the linkage cover and watch the action through the rev (don't ask). I was going to change the spring, but it is kinda neat, you can clutch it to get it to switch, then bang gears runnin like a revin little 2-stroke, or putt around like a scooter going flat at scooter rpms, then shift, kinda stealthy. I am sure one could soften the spring and make a more seamless transition, but it is kinda like Jekel and Hyde now. When I first put in the PV, I thought it lost all top end because I didn't let it rev through the flat spot, I was lovin the low-end but very disapointed with the overall performance, a few rides later, after break-in, I power shifted using the clutch and walla... I discovered screamin top end, man was I happy, I can have my cake and eat it too!

Edited by TurboStew

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