I have a 2 yr old Husqvarna push mower with a Kohler engine(from Sears). Early in the summer the engine ran with a miss and leaked gas. The problem was a loose carb and tighting the it fixed the problem. I was using the mower this week with the bag to pick up leaves and the mower ran low on gas, when I refilled tank the mower would start up and then quit and it was leaking gas again. The carb was not loose this time.Air filter clean,fresh gas in tank;any help with this problem would be great. Model #917.384510