My riding mower won’t start …
Spring is here and time to start cutting the grass. We have a riding mower, after one time of mowing, we could not start the mower. The engine humming but not start.
As a newbie on engine, I thought it must be a dead battery (even though we took out the battery for the winter and charged it). After bought and put in a new battery, same thing, the engine refused to start.
Called technician, they were really busy so I booked an appointment 2 weeks away. We used an old push mower cutting grass, it took a long time to finish the whole yard. I could not help but want to figure out why the engine won’t start.
Youtube has a terrific video to help diagnosis mower engine problem. I followed the steps, bought starting fluid, and again, engine did not start. So I went on to troubleshooting the potential spark issue as the video suggested.
I changed the spark plug since I need to maintenance work for the mower anyway, nothing changed. Bought a spark tester, no spark at all. So next step is ignition coil.
Took out air filter, open the engine cover, there were a lot of dry grass under the cover. This mower tends to get grass into engine parts, but the amount of grass and many white pieces like fiber or paper looked really suspicious. Moved those grass, it was clear right away where the issue was. The ignition coil was burned at the bottom part and part of plastic cover of the cable was off like been bit off. I recalled my wife told me that she saw a mouse next to the mower from time to time. It must be that the mouse built a nest under the engine cover during the winter (maybe even prior that) and along the way, bite part of the cable cover. Somehow either the exposed cable touch the metal engine part or the engine heat built up in the dry grass damage the ignition coil.
Called the local John Deere dealer and they have one ignition coil in stock, I happily drove there and pick it up. Changed the coil, tried again, unfortunately, it still did not start, no spark!? I was puzzled.
While checked the engine and read/learn more about the engine start process, I realized that, the humming sound came from starter motor — the starter motor worked whenever we tried to start the engine, it spun and spun but did not engage the the flywheel, that is why there was not spark.
Quite odd issue, after a search, one post on houzz seemed to suggest the battery could be problematic. That was interesting, but engine did not start and I had the old battery at hand, not reason not to try. Switch the battery, the engine magically started!
long story short, I encounter 2 weird issues, mouse built nest under engine and destroyed ignition coil, and I bought a battery that has positive and negative reversed. Fortunately both of them were fixed quite easy.
