yo. ive been kicking around the idea of making an expansion pipe from the ground up, starting with all the calculations. i prefer motobecane over puch, but i dont wanna have to tackle a ball joint and crazy moby mounting and such for my first pipe... so im doing one for a stock puch maxi. i dont even own a puch right now (my friend's bike will be the guinea pig), so i figured some of yous dudes would have some info for me.
im just looking for some rough info that you might already have written down somewhere for a couple things: first thing i need is port open duration of a puch stock cylinder. rough idea is fine, port height is fine too i can take it from there. anything you got. next thing i'd need is a basic idea of where the peak RPMs would be for a stock puch maxi 2-speed. cant get it w/o a tachometer, and i can calculate it via mph and gear ratio and such but i dont feel like that's as accurate. it'd be good to have an idea of what other people have already measured.
i just want a basic idea of the proper numbers so i can mess around with plugging them into jennings' formulae and whatnot. this way once i get the actual data from the bike i'll actually know what to do with them, and i can just plug and chug. think of it as a practice round.
thanks for the help,