My bobcat 463 serial no. 522211884 F-series will only start when I take the hydraulic belt off. I have been messing with this for a while now and was looking at engine problems. Well, after practically rebuilding the engine I happen to notice that the tilt cylinder was trying to tilt down as I cranked it. So, I though just for the heck of it I'll take the belt off and see what happens. Well the thing started. Is there a valve or switch or something to look for? It's acts as though the pump is under pressure not allowing the engine to turn over fast enough. Thanks for any help you can offer. Don