i have a piaggio diesis 100 air cooled and was wondering would i be able to buy another engine e.g speedfight 100, gilera runner 125 and be able to fit it on top my frame?
anythings possible with skill and a welder. However for pretty much most people its not easy or achievable.
The only swap that'd be worthwhile would be the runner engine. Even then it'd be easier/cheaper just to buy an actual runner and sell your own bike. Whats wrong with your current engine?
nothing is wrong with my engine its just i struggle to find parts for it as its not a well known bike
best advice i can give is to go with bike that are well catered for. I brought a sym cheap. their was pipes and little bits around for it but no where near what an aerox or similar has on offer. either love the ped as it is or trade up and get a bike you like that has aftermarket parts readily avalible