Author Topic: KX119 Supermini Hillclimber  (Read 3947 times)

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Offline GREENKAW24

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KX119 Supermini Hillclimber
« on: April 07, 2013, 11:48:48 AM »


Bike we built last season for the 125cc Class. Will be 2nd full season for this bike ridden again by Jason Larivee Jr. (5th place overall in 2012)
54.5mm bore x 51mm stroke

Offline sandblaster

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Re: KX119 Supermini Hillclimber
« Reply #1 on: April 07, 2013, 01:53:45 PM »
Nice!
Care to share some details?  :-D
Nothing that is super top secret....  :wink:
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline riproost

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Re: KX119 Supermini Hillclimber
« Reply #2 on: April 07, 2013, 02:57:36 PM »
Cool...Looks like all business!
got any video of the 125 class?
RipRoost

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Re: KX119 Supermini Hillclimber
« Reply #3 on: April 07, 2013, 02:59:31 PM »
Cool...Looks like all business!
got any video of the 125 class?


I still watch your video fo the 200cc class Bultaco all the time ..         thinking I need to modify my campera...........

Offline motopunk

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Re: KX119 Supermini Hillclimber
« Reply #4 on: April 07, 2013, 07:11:11 PM »


Bike we built last season for the 125cc Class. Will be 2nd full season for this bike ridden again by Jason Larivee Jr. (5th place overall in 2012)
54.5mm bore x 51mm stroke

nice bike... if it runs like the amazing look, it will be a little monster...  :-D
big 2 stroke bikes are weapons for real men, who don´t fear death or devil. ;O)
´83 kx250, ´87 kx250 (with 360 big bore), 87 kx500, ´93 kx500 sfc

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Offline GREENKAW24

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Re: KX119 Supermini Hillclimber
« Reply #5 on: April 07, 2013, 11:18:54 PM »
Nice!
Care to share some details?  :-D
Nothing that is super top secret....  :wink:

Started as 2004 KX85, has a 17 inch rear wheel, 19 inch front wheel, 33mm Keihin carb, 5mm stroker crank, VHM Head, VHM reed valve, Hybrid KX85/KX125 custom exhaust.
5mm is the absolute most you can stroke this motor. The transfer timing gets too high, even when cutting the stroke clearance into the head instead of raising the cylinder. Not enough blowdown.
Most people stop at 112cc when making this motor a Supermini, we figured we could squeeze a few more cc's out of it.
It competes against all the standard sized 125cc MX bikes.
The pros of his bike are that the HP is so close to the 125's, and it is 40-50 lbs lighter.
The cons are the suspension travel, and the wheel diameters.
Last season was spent dialing in the gearing/jetting/suspension, and the young rider getting used to the bike.
I don't have videos, as I'm either riding or wrenching all the time, so I don't record any myself.
There must be some out there though.
Its definitely an impressive little bike.