Lawnmower boy, part two

Lawnmower boy strikes again. I asked him to mow the lawn after dinner. While going upstairs, I saw a green blur fly past the window - Lawnmower boy! He was cutting the grass at mach 6. I heard a sonic boom after he passed the window. I ran outside to slow the boy down before small animals were maimed, but I couldn't catch him.

At about the same time, his mother realized this was happening and was bellowing at him from a second story window, but alas the roar of the engine and the wind whistling in his ears were too loud. I finally caught him rounding the corner of the house and he skidded to a stop. After I informed him that he was going too fast, he slowed the tractor down one notch. I had to be the fun governor and put the transmission on 3, rather than 8 where he had it (the highest setting). I think he left skid marks on the lawn. The wife laughed for 20 minutes.