Simply stunning.
Why not both? When the batteries die, start the gas motor. That is a very nice frame, by the way.
I'm thinkin a GX120 or an electric start GX160 in addition to the electric motor would be the cats meow. It would be a purrrfect hybrid setup if money was no object.
It's lookin good, don't stop now....
I agree with Scotto, a GX120 should fit easily.
Seems like you already have a gas tank on the bike.
My sidecar bike has a GX120 clone, 160 bucks from Home Depot:
http://www.homedepot.com/p/LIFAN-4-HP-118-cc-Horizontal-Shaft-Engine-LF160F-AQ/203281927?N=5yc1vZbxc9Z543
My bike probably weighs as much as yours does, and it will cruise at 30 mph with the 120cc engine.
B
So load the ammo cans with bricks, strap a sandbag or 3 to the engine mount & launch it off a curb a few times.
I would want to know the frame was ok before I put 2k worth of batteries, motor & controller on it.
.
I Agree with FFV8. Load it up and take it over a coulple good pot holes....see if that rear section holds up...
You don't have seatstays, that's the problem. You should make some.
What you have is a "rack" The vector is not there between your butt and the rear axle.
I know. We've been through this all before many times. You have big pipe and it's really strong. Good for you. Big pipe is where it's at. Big welds and big pipe. Strong.
You are still laughing and I'm done.
Good Luck!