id say yes that would probably give you some good speed.
A 115CC engine is fast for a go-kart. It should enable the driver to get some good speed. You can also use a 110CC engine.
A 115cc go-kart can typically reach speeds of around 30 to 50 miles per hour, depending on factors such as the kart's weight, design, and the terrain on which it's driven. Performance can also vary based on the engine's tuning and the type of tires used. Generally, recreational go-karts in this range are designed for safety and control rather than maximum speed.
There is no direct conversion between cubic centimeters (cc) and inches, as cc is a measure of volume while inches is a measure of length. You would need to know the specific dimensions of an object to convert cc to inches.
16ounces =454gm approx454 /125 = 4.4 oz approx125 grams is 4.41 ounces.About 4 1/2 (28.3 grams to an ounce)