Performance (Motocross) mods for KX100


tyler_43

Member
Jun 22, 2007
126
0
hey, i was wondering if there's anybody out there racing a kx100, and if so whether they had any mods they liked in particular. Mine's stock other than renthal bars, fmf-shorty and boyesen reeds... but is anyone running a Pro-Circuit head pipe, 105 kit, porting etc.? I'm racing in the 125 class so I could use the power. Thnx
 

Jan 3, 2007
1,860
0
tyler_43, my friend has this bike and there were 4 parts that make this bike awsome in the 125 class.
1. A FMF Fatty dose wounders for everywhere power.
2. one tooth lower on the front makes the 3rd and 4th gear more usably.
3. Porting for top end power, and milling the head for more compresion give this bike lots of top end sailing.
4. suspension set up for your weight and and style will also help in the corners and the bike flys better.
The best one would be the pipe, the gearing, motor work, and then suspension in that order by bang for the buck wise. Hope this might help.
 

MagnaTrey

I'm Motorcycle colorblind
Jun 19, 2007
41
0
Hi Tyler,

A few questions.. How much do you weight and what class do you race, how aggressive are you, how much money are you looking to drop into it, etc
It would give me a little better idea for suggestions.

If you are looking just for power, the old adage rings true, especially in small displacement bikes; "nothing substitutes displacement". Stroke it to a 112.

I'm in the process of having it dyno'ed with a couple of pipe configs, FMF vs Pro Circuit. When I get those back I'll post them if anyones interested. I'm guessing it to come it at about 27 to 28 at the rear wheel with everything I've done to date, but we'll see. :cool:




2006 "KX112"
Stroked & Ported.
Pro Circuit & FMF Pipe's
Pro Circuit Shorty & FMF Silencers
V-Force3 Reed block
FluideDyne aluminum 10 core radiator
Hinson Clutch Basket
Pro Circuit Valving - Front & Rear
RAD/Excel Wheels
Braking Wave Rotors
Twin-Air Air Filter
ASV Forward Control Levers - Clutch and Brake
Galfer SS braided brake line - rear
Black Number Plates W/ White BG's
White Brothers Tri-Pro Foot Pegs
Works Aluminum Frame Guards w/ custom grip tape work
Boyensen Racing Ignition Cover
Renthal Aluminum Bars
Works Aluminum Glide Plate
PE Billet Throttle Tube
Turner Aluminum Billet Gas Cap
MSR Forged Aluminum Shift Lever
ASV Black Aluminum Rotator Clamp
Napalm Aluminum Air Filter Bolt
Black painted Plastic body accessories
 

helio lucas

~SPONSOR~
Jun 20, 2007
1,020
0
from what i heard that bike carb is a little small to do good power, but the original cylinder might have to be ported...
 

whenfoxforks-ruled

Old MX Racer
~SPONSOR~
Oct 19, 2006
8,129
2
Merrillville,Indiana
derek the 2 stroke said:
Stroking is illegal in motocross isnt it?
I believe you are correct. For what its worth,I assumed they do not have a clue,and are talking about boring. And he is in fim country,I am not up on their class specifics! Pics of the 10,000 dollar KX would be appreciated!
 

MagnaTrey

I'm Motorcycle colorblind
Jun 19, 2007
41
0
whenfoxforks-ruled said:
I believe you are correct. For what its worth,I assumed they do not have a clue,and are talking about boring. And he is in fim country,I am not up on their class specifics! Pics of the 10,000 dollar KX would be appreciated!


Stroking in my neck of the woods is legal if staying within the displacement requirements. So, 112cc in a 125cc class is ok, and stroking has nothing to with this issue because he is running in the 125cc class.
 

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MagnaTrey

I'm Motorcycle colorblind
Jun 19, 2007
41
0
dirtbike_freak said:
Thats a sweet bike.

Thanks much DB_Freak. It's is an absolute hoot to ride. The power to weight ratio keeps things interesting to say the least. The only problem I have as of now is the fork flex when I stuff a berm. I'm definitely upgrading the triples. The stockers are wimpy, wimpy, wimpy..
 

whenfoxforks-ruled

Old MX Racer
~SPONSOR~
Oct 19, 2006
8,129
2
Merrillville,Indiana
Awesome looking bike. Yes ditch the clamps and Wilkey has some top notch tips on setting your forks. Do you keep the flashing off the tubes and clamps? Stroking around here is changing the pistons length of stroke. The best MX mods for HP is to bore for a bigger piston!
 

150rguy

I got fat bars!
Member
Dec 21, 2006
654
0
You could stick a number 7 on it and say it was Stewarts old bike.
 

MagnaTrey

I'm Motorcycle colorblind
Jun 19, 2007
41
0
whenfoxforks-ruled said:
Awesome looking bike. Yes ditch the clamps and Wilkey has some top notch tips on setting your forks. Do you keep the flashing off the tubes and clamps? Stroking around here is changing the pistons length of stroke. The best MX mods for HP is to bore for a bigger piston!


Thanks FoxForks, I appriciate the kudo's.

I occasionally do peruse Jeremy's neck of the woods. He's is definitely knowledgeable.. :cool:

As far as the bore issue, it is bored 54.5 with a +2 hot rod with a 85cc cylinder, machined valve, and head milled for proper squish.

Regarding "Do you keep the flashing off the tubes and clamps?" I'm not familiar with the terminology. I'm just a little lost, sorry my man (or gal).

~T
 

MagnaTrey

I'm Motorcycle colorblind
Jun 19, 2007
41
0
Quote:
"You could stick a number 7 on it and say it was Stewarts old bike."


Only if it made me a fast as Stewart.. :nod:
 
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150rguy

I got fat bars!
Member
Dec 21, 2006
654
0
MagnaTrey said:
Quote:
"You could stick a number 7 on it and say it was Stewarts old bike."


Only if it made me a fast as Stewart.. :nod:
Are you the one that rides it?
 

MagnaTrey

I'm Motorcycle colorblind
Jun 19, 2007
41
0
whenfoxforks-ruled said:
Your clamps are aluminum,filthy dirty aluminum. Remove that grey crap and presto,clamps hold the tubes again!

Ahhh, Aluminum Flashing = Surface Oxidation.. I got it ... No, the most I do when I have my forks off for servicing my just wipe it all down and clean, clean, clean... But it does sound like an interesting concept. I'll have to definitely look into the process. Thanks FoxForks.. :cool:
 

MagnaTrey

I'm Motorcycle colorblind
Jun 19, 2007
41
0
150rguy said:
Are you the one that rides it?

Ride it or just twist and hang on; I guess it depends on your definition of "ride".. :yikes:
 

MagnaTrey

I'm Motorcycle colorblind
Jun 19, 2007
41
0
hot125mod said:
magna trey what fuel do you use in the 112?

Hi Hot125,

Right now I'm not running max compression, so I'm dumping 93 pump at 32:1 into it.
 

MagnaTrey

I'm Motorcycle colorblind
Jun 19, 2007
41
0
It's a 84cc cylinder bored to 54.5mm with a +2 hot rod.
 

MagnaTrey

I'm Motorcycle colorblind
Jun 19, 2007
41
0
No worries, I do this all the time ---> :bang:

Fresh build, 205psi @ 350ft/40%/80f
 


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