Yes I have the pro cut 61. I figured the tire problem out. They were the correct size just the wrong profile. The mounted flat profile when I needed a round profile.
Right now I have it tore apart. Pulled the heads. Not running very well. Bogs way down under a load. Thought it might be the valves. They checked out ok. I already cleaned the carb right before it started acting up. I'm also getting oil in the airbox. I checked the crankcase vent box it looked ok. There is no wet oil in cylinder so I don't think its rings.
Also is leaving grass uncut, just little strands here and there. Looks horrible. Had my Ferris dealer sharpen blades, same problem.
The motor is a briggs vanguard 20hp