I have a nice Hampton Cruiser totaly customized. is now a 7 speed, so I added both front and rear hand brakes. and fat street tires. I am confortable adding a motor to this bike. I have a 25 cc old leaf blower 2cycle motor. but I am probly going to buy a Robin 40cc 2 cycle motor for this project. I wanted to say High and introduce my self to anyone that cares and see if I can get a genius or 3's attention, I am about to dig into this thing. Say hi if you have something to offer. anyone know where to get or how to make a manual clutch? I am having some issues with the plans I have going on in my head, like where is this kind of clutch found? like hand cable operated. also, has anyone considered a bicycle hybreed. like an electric hub motor and a 40 cc motor generator como and one of those ebike controlers? seems like it the power head could be easily removed for security , carry it along or to service. just an Idea, Jim.. 
Welcome to The forum. All you need to build a dry clutch is a factory a lot of $$$ and a degree in engineering. Or a centrifical clutch and a way to adapt it. Western Auto has them. Also PeP Boys, I think? Why not take a look @ Dax & Spookytooth motors. Also Ebay but their like a box of choclates, You never know what you will get. 
of mind members of our forum have to offer. I have a question or other Duane and Spooky are right on it!
