If you own a two stroke then you need John's book on how to tune it. This book along with a Graham Bell's & Gordon Jennings are a must for the "kitchen table" & the very serious tuners.
John wrote a computer program one of the first for designing expansion chambers for 2 strokes (which is in the appendix of the book) , which is now obsolete as the BBC b type computer is now a collectors item.
I had the great pleasure of working with John an re-writting it in DOS for the PC alas that too is now obsolete. BUT the math is still valid and any script kiddy could do amodern version .
The basics are here and will lead you on to looking at Prof. Blaire's extensive works.