Ok, got an extra lawnmower late last year, a self-propelled one since my son is starting to help out. It’s one of those that you have to add some oil to the gas. I only added gas to it once last year before the end of mowing season. This year I pull it out and top it off and start to mow. Get through half the front yard and it shuts down on me. Now the string won’t even budge for me. Then the idiot light bulb goes on and I realize I didn’t add the oil to the gas when I filled it up. I am not mechanically inclined at all. So what did I do and how can I fix it?