(I"m OP, and the engine is actually the 79cc version of the Predator) It will never be a finished project as there will always be improvements possible.
The current state of build is different form the big pic in that I moved the gas tank to in front of the bike (secured to the frame; not the handlebars).
The bike does OK on the flats, but the roller-tire contact doesn't provide enough friction to transfer enough torque for a good hill. Also, the roller, made from wood, wears down after a while. This lowers the gear ratio and eventually causes the engine-support frame to rub the tire.
Yes, it's certainly better than a plain bike, but there's plenty of room for improvement.
On the next one, I won't have the motor & roller bearings both fixed to the same mounting-frame. The clutch needs to operate without the weight of the engine.
Every day, people compliment me on it , but I can't take much credit because it wasn't complicated to put together. I believe a man (girls are excused) *should* at least have this much mechanical skill. I also don't deserve being told "good job" because I don't see it as such. If my father were alive, he would be critical, and I model him in my mind for judgement sometimes. (I'm using public WiFi and I have to go , so I'll post now.)