As of October 2015, websites for Green Parts Store, John Deere and Amazon.com sell John Deere spark plugs. Green Parts presents user ratings and reviews on its site and recommends that customers also purchase a spark plug gap gauge.
John Deere's online store offers several different spark plugs that fit a variety of models of lawn tractors and snow blowers. The site features a page with riding mower care videos, including a short clip of spark plug maintenance. The video explains the reasons for changing spark plugs, the tools necessary and the steps involved.
Amazon.com sells spark plugs through the John Deere site. User reviews and ratings are not available for all spark plugs.