Replaced the O ring at the bottom of the filler tube with a match from the hardware store. Dealer only will sell the entire filler tube. However, I may have over-tightened the lower bolt and cracked the tube. Now we will wait and see. I ran it for about 10 minutes and watched. No leak. The tractor sits at a small angle to the left in the garage. It never leaks while it is running on level ground. Fingers crossed!