Hello all, last winter I purchased a Meyers VB750 manure spreader. It was used supposedly "refurbished". I used it for 7 loads and chain kept jumping and getting off a cog no matter how tight I tightend the chains. So I complained to dealer I got it from so they sent me new sprockets. I didn't make time to replace sprockets until last week. Yesterday I started hauling again and same problem. Chain jumping. So it tightend up and now it doesn't jump but it doesn't have enough power to unload itself unless the peak of my manure pile is a foot below the sideboards. Tractor is an 8245r john deere. Tried 8420 and 7810 deeres as well. Im getting very frustrated with this spreader as I can only haul half loads. Anybody have any similar problems with these spreaders? Any simple fixes? Orbit motor bad? Thanks!