I'm trying to repair my tractor Its 3 years new just gave it a tune up because after running about 45 minutes the engine started speeding up and slowing down rapidly and seemed like it wasn't getting any gas it just stalled out. After replacing spark plugs, gas and oil filters the next day it ran for 10 Minutes and shut down the same way I was told to check the gas cover vent hole. I went to a John Deere dealer looking for some advice and hope's that it would be a minor problem. He thought it could be a blown engine gasket. I'm surprised that there aren't more people having the same problem. If someone has had this happen to there John Deere LA-140 mower please respond to my thread. Thx in advance