I have a three year old John Deere riding mower (E170), which all of a sudden developed a starting problem. I was mowing my lawn, with it this past Saturday, and it performed well until I stopped mowing and turned off the engine. When I returned to finish my mowing I turned the key and it only made a "Rattling" sound and didn't turn over. At first I thought it was the battery so I bought a new one but it made the same rattling noise. Then my Brother said it sounded like the Solenoid so I removed it and took it in to see if it was the cause of my problem. The Solenoid turned out to be bad so I bought a new one from Lowes. I installed the new Solenoid but my John Deere still wouldn't start just made that "Rattling" noise. I've checked the wiring but everything seems normal, so I am baffled as to why this three year old John Deere riding mower won't start. It has plenty of gasoline and the oil level is at normal. Anyone have an idea what's wrong with my riding mower?? <Thanks>