One word. Parts. There are no hi-po parts available, so..... you'll have to make your own or find something similar to work.
We really
do know what to do, it's just prohibitively expensive to do for the very minor gains you are going to get. Even with a 25% gain (highly unlikely) you're going to make 23 hp maybe???
Why not just get a bigger bike that those type of parts are available for? You'll spend less and get more in the long run.
But...... I guess you know better than the 300 or 400 of us who've been there and done that.
I's your money and time. Have at, I'm done.
:??:
:whistle: