When you say you want to unlock its full power can you be little bit more detailed what you want to achieve out of it, then we can definitely guide you the direction in which you must move.
On the other hand the Stock top speed of SR150 is 90kmh with good feul average and keeping engine safe and 110kmh with abusing engine and destroying feul economy.
If you are already getting these figures you are in good spectrum with this enigne the bike has.