I have a 2006 36" 13hp Kawi belt drive Toro Proline mower with 2 issues. 1st - The left side drive often binds up (the brake lever is pulled up without me touching it) causing the brake to engage lightly (no abrupt turns). Sometimes it releases on its own, but usually I have to come to a complete stop for it to release. I have taken this side apart and could see no problem and all parts seem to move properly when it is not bound up. Any ideas on why this is happening and how to fix it? 2nd - It does not idle smoothly. With the throttle lever at the bottom of its travel, the engine rpms cycle up and down within a relatively low range. To get it to idle more smoothly I have to pull the choke out carefully to find the sweet spot. Thoughts on what is happening here and a solution? I would appreciate your help very much.