Have had this skidsteer since 2007. Been a great machine, a real power house. Have it tore apart in the barn addressing some issues and getting ready for paint. Throughout the years, sometimes I will loose my drive on the right side. It will eventually quickly start working again after I hold the stick all the way forward or back, comes back very violent when it does, and it may not do this again for months. I am suspecting it is a spool issue. It is cable to the valve. Bobcat tells me those parts are expensive and they are telling me to look for leaks at the valve? Has anyone else had this problem? Wanting to get this repaired while I am into it.
I had the exact same problem (machine would barely move, then rocket forward when stick fully extended). There is a shuttle valve in each hydrostatic motor that can be of issue. I had a BobCat mechanic work on it without success (and my pocket book was about a grand lighter when he was done, still not reseolved). I ended finding a replacement (rebuilt) hydrostatic motor, installed .......worked like a charm. I'm not sure, but I think it was loader part source (they wanted the core in the deal...cost was about $750 total). My machine is a 753 C, so likely similar to yours.