you got it, well pretty close it is all about gear ratios. Gearing it down will make it quicker but will make your first gear almost useless. Changing the tire size is NOT reccomended because it screws with the handling characteristics. Id find a sprocket with 2-4 MORE teeth to make it quicker or 2-4 teeth LESS to get more top end. putting a smaller front sprocket on will work but it will also wear out much quicker, and a larger one will decrease clearance between the chain and sprocket cover on the engine.