It was the tires.BTW, 8.25R20 not 8.50.
Took them back to the balancer. On the machine, the one with 0 weight, said it needed 0 weight.but before it had even finished spinning the manager and I looked at each other and said "It's not round".
Both of them had serious flat spots. BTW, the one with 18 oz said it had 4 oz too much.
The place that sold them didn't seem suprised. They don't sell Double Star any more.
Finding me replacements. waiting for the call.
Several dealers sell the Double Coin for drive tires and trailers and have few problems.