Pocket Size Terror – Building a CRG ICC Shifter Kart


The front brakes are like the rear in that they use vented full floating rotors with a fixed two piston caliper. Shifter karts are different from regular karts as they are the only karts that are allowed to have front brakes. Having front brakes makes a shifter kart the fastest decelerating car around.  An ICC shifter is capable of going from zero to 80 to zero in under 6 seconds and can outbrake an F1 car.  CRG has super light weight ceramic rotors as a megabuck option but we settled for good old iron rotors.
The CRG has dual master cylinders with a balance bar to adjust brake bias just like a racecar but smaller!
Medium compound Bridgestone slicks were mounted on CRG Magnesium wheels.
We salvaged the two stroke, TM K9 ICC engine from the old kart.  Although we only paid a few hundred bucks, these suckers fetch over $4500 brand new.  The TM K9 features a straight cut dog shifted six speed tranny.  The biggest advantage the TM has over moto class engine is that the intake faces forward where intake air has a straight shot at the induction system and the exhaust is out back. A moto engine has the intake and exhaust reversed from this so they must curve around the engine to exit in the right directions. The TM K9's configuration allows a more straight forward exhaust and expansion chamber to be made without making the chamber turn 180 degrees.  These changes are part of the reasons why the ICC engine makes 10 more hp over the stock moto engine.  The TM K9 rocks out with an amazing 45 hp from just 125cc.
On a two stroke engine, low rpm reversion becomes an issue when you have radical port timing with a lot of overlap.  To reduce this reversion, modern high performance two strokes have reed valves.  The reed valve is a one way valve behind the carburetor that prevents back pulsing through the carb and keeps crankcase compression high at low rpm.  Our stock carbon fiber reed valves were starting to fray so we replaced them with these Moto Tassinari Delta 3 reed valves from Acceleration Karting.
The Moto Tassinari Delta 3 reed has twice the reed area of the stock reed valve.  This helps low and mid range responsiveness like soft reed valves do with the big top end that stiff reeds have but with good breathing like stiff reeds don't have.  The reed is good for a broader powerband and more overall power. 

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