Jetting

[mcsuicd3]

I have a piaggio zip engine build that I am fitting a performance top end air filter and a yasuni c16 road legal sports exhaust, I'm told I must upjet 20%more than the stock. However I would like to know the math formula for optimal performance jetting before tuning needle and AFM? does any body know the formula as there used to be a tool on 49cc scoot that auto calculated for you including hight of land according to sea level ? Can any one help ?

[aeroxbud]

There are so many variables with a built engine. No one formula will work.
Are you fitting an open pod type filter? What cylinder do you have to match the exhaust to.
The C16 is quite a serious exhaust. And marked for competition use only, as it has no restrictions. So not road legal in most places.