One of the most common and cost effective ways to boost your MSX125 / grom big bore kit is with a big bore kit. These kits bump the cylinder’s displacement from the stock 124cc to a ripping 170cc. This allows you to run higher quality pump gas and make the most of your engine’s performance capabilities. The kit comes with a ceramic coated cylinder, 61 mm forged piston, rings, pin, banjo bolts, and fresh gasket kit.
How much HP does a big bore add?
The cylinder has a unique coating that is electroplated with Nikasil (Alumina). This not only creates a stronger surface, but it also alleviates the heat generated by combustion. This makes the cylinder much more durable and reduces friction. The cylinder also has a high compression ratio that will allow you to use premium pump gas and still make great power.
Another great feature of the KOSO kit is the high performance camshaft that is included. This cam increases the air flow through the cylinder which helps to keep the engine cooler. The cooler running engine will reduce your maintenance costs as well as improve the reliability of your grom.
KOSO’s big bore kit is a great upgrade for your MSX125 / Grom and will give you that extra power that you have been wanting. The kit does not require machining of the cases so it is a direct bolt on. The kit also requires a fuel controller as the larger displacement will deviate from the ideal air to fuel ratio and you will need an adjustable fuel controller to ensure that your bike stays within safe ranges.