Today I was introduce to the a 59mm (increase of 6.6mm from stock bore size) chrome lined big bore kit for the 2013 Yamaha Mio125, making it a 158.3cc and I will make your 100 kilogram Yamaha Mio125 fly like the wind...

What I hear, is that, against expectations, the Yamaha YMJET-FI (fuel-injection) system used on the Yamaha Mio125 adapts much more to the big bore than you will see with other manufacturers small engine fuel-injection systems for small bikes.

With a bit easier breathing and bigger, less obstructed exhaust system the Yamaha Mio125 can actual be turned into something I would never expected... a DANGEROUSLY FAST scooter....

Are you familiar with any bikes which have actually had this modification?

Quote by: ThaiDesign

Today I was introduce to the a 59mm (increase of 6.6mm from stock bore size) chrome lined big bore kit for the 2013 Yamaha Mio125, making it a 158.3cc and I will make your 100 kilogram Yamaha Mio125 fly like the wind...

Bit late here but where were you introduced to this? Poonsub Market or somewhere similar.

It probably means there will be an overbore kit for Tricity?

PCX 125 can be done to 165-170 cc or 185 with an offset crank pin.

We one time modified a Yamaha Fino with a 189cc bore-up kit and learned that it was outright dangerous to ride. But with the Yamaha Tricity, which is much more stable than the Fino it probably would be more stable at higher speeds.