I have a Sears 18hp twin that runs okay. I noticed the other day when I got it running and engaged the pto for the mower deck, there was a slight wobble to the mower as it was sitting still. I hope to check into it further tomorrow. Off the top of my head I would think it could be the blade(s) are not balanced or one of the spindles is not turning in unison with the others(belt slip or bad spindle bearings). Any thoughts??
Edited by trackcar, May 09, 2014 - 08:26 PM.