Ok I'm trying to get a newly aquired tandem going (thanks tlaing1) anyway the only real problem is the chain tensioner doesn't sit tight. It's a bolt through a pulley with a square block and a nut on the other side. I'm assuming the block was threaded at one time and the nut was added later (it was the wrong thread) I took the nut off but CAN NOT get the bolt out. I've tried using a puller to push the bolt out. I've pried prying on the pulley and slowly turning the bolt It just spins and spins and spins. I don't have the right size nut in stock and would like to get this thing going. I'm assuming that the square block on the inside was threaded at one time and is now stripped and I can't get the threads through it for one reason or another. If anyone can offer any help it would be greatly appreciated