Porting
Porting is not for everyone. The first thing that you need to ask yourself is do you use all of the engine's power when riding? If the answer is no then you do not need top end porting. Do you use low to mid-range power mostly? Then porting to bottom end and mid-range power might be for you. Keep in mind that generally what you add to the top end you will take from the bottom end, and vice versa. You can port to give a good mix of all ranges, but the gains will be less on all 3 areas than if you were to go for top or bottom only. Make sure that porting is for you, if it is not and you do it you will most likely not be happy and there is no going back. You would have to purchase a new cylinder and start over again. Porting can yield top end power, hard hitting mid range, and very torquy low end power.