Well, I have to agree with Jim, I've done all kinds of mix and matching using Puch as the base, and different types of carbs. Trying to find or make an intake manifold to accomodate the different carbs are usually the tricky part. Back in the late 70's, I actually found an old Mikuni carb for a 125cc mototcycle, and used it. I had to make the intake manifold out of a regular garden hose. The thing actually worked, ran great, and hauled butt. But, having the flex in the hose kinda shook the carb around, tossing fuel out of the bowl constantly, kinda made it a scary ride. Not fond of smelling gasoline and having gush out all over the place down at the feet area, not fun. I now have taken a 17mm Bing (the regular make of carbs that came with the Puch series) and intake manifold from the Puch Magnum X motocrosser moped/motorcycle, never figured out if the Magnum X was one or the other legally. Anyway, the 17mm Bing is one of the best additions I have added to the beast, as well as the 70cc kit, and an expansion chamber I robbed from a dirt bike. (not fond of the BiTurbo, other than its looks, plus the massive backpressure cauing it to get really hot).. 63mph gets a bit hairy on these things, the suspension isn't really designed for this kind of speed, the speed wobbles appear at around 55-60. Gets scary to say the least. Once the wobbles start, dropping down to 40-45 to stop them is a must. So, as Jim stated, the right fitting and jetting will work on just about any mix and match you can come up with. As long as that intake port is getting the proper fuel/air mixture, fun is all you will have!