Looks like it works as is. How much slack on the chain when the shock is compressed? i'd worry i would hit a bump and chain would come off without a tensioner.
and yah RED ROCKET, my thoughts exactly BOB. But the next couple images of it mounted looked okay actually. I was thinking whats wrong with the cruiser looking tank. It kind of makes it look more dirt bike with the small fire extinguisher tank.
Looks good so far.
p.s. 3.5HP......find a 5 or 6.5HP. depending on who is riding a 3.5HP it will be slow, might as well keep the cruiser look because that's what you will be doing.