The problem was that the small spring toward the front of the mower that pulls the tension on the idler arm with the Varibale pulley and idler pulley (I think both pulleys are on the same arm) that holds the tension on the drive belts had come loose from where it hooks to the right side frame rail. (There is also a large spring that pulls toward the rear of the mower) When I hooked it back up, the spring seemed to be weaker that what I thought it should be. Maybe that is the reason it came loose. I mowed my yard with it and the belts seemed to slip a few times while going up a steep grade. I think I will replace the Spring or both springs.
Thanks for you thoughts on this problem.