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TTR125 Big Bore Kit Test


As mini madness continues to explode and a little red Honda XR100 keeps was the leader in the hot rod minis.  The Yamaha ttr125 dominated in the suspension and braking and overall handling, but it is very down on power.  
Motorworks send us there big bore 150 kit. I hope it runs as good as it looks it is shiny gold and a very short piston like at 250f.   The piston had a short skirt and had a polydyn coating on the inside and the top.  This is the first time I've seen it on a mini piston.  The kit came with a pilot jet and a main jet and detailed instructions.    So we got started.  

Installing The kit was pretty straight forward. While the motor was apart, we were installing a Webcam and cleaned up some of the bad casting on the ports.  So now it's time to unleash the power. We did the airbox mod and added the Jets. We broke in the kit slowly, then we went to the track and now we can pull away from the Honda XR120 s on the straight and specially the hills. Next we installed a 24 mm Mikuni and a stepped exhaust pipe, which is a must with the big bore kit. On the track, we toyed with the little Honda XR120. After a whole year of racing Adult mini racers we pulled the TTR motor apart to see how it was holding up and it looked fine.  So we put it back together to be ready for another year. 

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