The Kawasaki KLX110 Modified to 138cc Dirt-Devil

We all have kids, and we all like to keep them happy. A Kawasaki KLX110 mini dirt bike will do fine, but a modified KLX110, turned into a 138cc little dirt devil does miracles.

A indicated we started out with a stock Kawasaki KLX110, went online and called some local Thai suppliers. The stock 110cc engine is just a memory thanks to a Takegawa Superhead with two big valves and a 138cc Takegawa cylinder. Te feed the non-stroked engine, the stock carburetor was ditched for a 26mm Mikuni with a Two Brothers Racing air filter and bracket kit. Handling the extra power is a Takegawa six-disc clutch with a manual cable clutch and cover in place of the stock parts. In the transmission, a Takegawa four-speed shift drum made the use of fourth gear possible, and a BBR heavy-duty output shaft reduced the possibilities of failure. A Two Brother Racing exhaust system rounded out the engine modifications.

The stock frame on the Kawasaki KLX110 hold up to a lot of abuse, and for this project little dirt devil, the frame was about the only thing we didn't touch. Marzocchi forks handled the suspension duties up front, and a Race Tech shock took care of the back half of the KLX110. The trick Two Brothers Racing swingarm was longer and stronger than stock – and also looked way better. Kawasaki KX85 wheels with dics brakes. Drum brakes, a fast motorcycle and a fast rider never mix well. Sik Tendencies brake adaptors made the use of the KX65 calipers possible, and a Two Brothers Racing brake pedal fit nicely with the Two Brother Racing footpeg bar.

The modified little Kawasaki KLX110 (KLX138) not only looks fast, it is fast. The two-valve Takegawa head is the key ingredient in the big boost in power. We've ridden KLX110 motorcycles with 160cc kits and stock heads that weren't nearly as fast as our modified Kawasaki KLX138. Getting the fuel in and out of the engine efficiently is more important than huge displacement. The engine started easily and was crisp and strong from idle all the way to the rev limiter. We never had an issue with a bog or hesitation, even when landing from big jumps or hammering through the whoops. It was a fun machine to ride.

The Race Tech shock was very sensitive to compression and rebound adjustments. It took a little work to get it dialed in, but we were happy with how the motorcycle handled once the front and rear suspension were working in harmony. Marzocchi has the mini bike fork world on lock down, and as always, we were happy with their forks. The Kawasaki KLX138 felt planted and handled some big hits without blowing though the stroke to the stops. Mini bikes are a blast to ride and even more fun to race. And for some who might not be able to afford a new motorcycle, taking a mini bike and making it awesome over time is a “fun” option. Hard to forget that we build this little Kawasaki KLX for one of the kids...