Here is the latest build that I did. The bike is a Huffy Karaoke Cruiser from good ol' Wally World. I'm pretty sure that it's basically the same bike as the Cranbrook. The white, orange, and black color scheme really got a lot of compliments, though.
The motor is an 80cc motor from Zoombicycles Motorized Bicycles,80cc and 50cc Bicycle Engine Conversion Kits,Bicycle Motors,Bicycle Engine Kit Parts
They have a deal where you can buy 6 at once for about $125 each with shipping included. This was only my second build. The first was a 80cc from bicycle engine kit, bike engine, bicycle engine, bicycle motor
I've had no major problems with either motor (and dax was the only dealer that seems to have absolutely no negative feedback here on the forum - his service is excellent), but the motor from zoom bicycles did seem to run smoother from the get-go. It seems to pull hills a little better, too. The zoom kit comes with a custom front muffler-clamp style bracket which I liked.
The whole kit basically went on the bike with no major modifications. I wrapped Hockey tape around the frame where the motor and tank bolt on. I ground the lip off the dust cap on the coaster brake so it would fit through the center hole on the sprocket. I also used only the inner rag joint. The outer rag joint pushed the sprocket out so far that the coaster brake lever could not engage. With only the inner rag joint, the sprocket is pulled tight against the hub - the whole thing seems to have worked great. I'm not sure if the outward pressure on the spokes will cause problems down the road or not. I'll just have to keep an eye on it. I also bent the coaster brake arm a little to make it line up right.
I had to add a couple washers to push the rear chain stays out enough for the chain to clear. It's a tight fit - wants to hit the tire on one side and the chain stay on the other. Seems good now, though.
I've seen that a lot of people have to fabricate a front motor mount for the cranbrook style bikes. With the clamp mount included in this kit, I didn't need to make any further modifications. The carburetor just barely fit, but it did fit in with no modifications. If I build another one, I'll probably just cut down the intake pipe a little bit.