Riding mower cranks but won't start

Picked up a John Deere LX 255 Riding mower on craigslist that wouldn't start. Diagnosed the issue as the backfire solenoid and show how to fix/replace. How to make money on Craigslist. Bought this mower for $125 as a no start. Spent $0 to get it running and clean it up. Sold for $500.