How much HP do you want?
How much can you afford?
 Most of us own scooters that cost less than $700.00. Even though HP parts are expensive many people are willing to spend  additional money to enhance performance not realizing the hidden costs. Increasing output by 10% can decrease motor life by 15%, this figure is exponential. Higher output means increased torque which is relative to drive system stress ( main, clutch, transmission, sprockets, chain ect.) then back to motor casing and engine mounts . Keep hidden costs in mind when enhancing performance.