I've got a ride on unit with about 75 hours on it. When i push the levers forward to go it will bind up and almost stop. I can release the levers a little and push forward again and it will start to go. I'm not able to aerate at a fast speed, but everything works fine at the slower speeds. So you are constantly "feathering" the levers. I took it to my exmark dealer and of course it wouldn't do it. We did notice that it was pulling to the left. He wasn't very familiar but said the chains might be binding the transmission. He was going to call Around to other dealers. I tried to get it out and catch it on a video but ran out if time. Any clue?