I have a Toro 36 WB with the Kohler 13 engine, which I use for my own lawn. It's a 2000 model, with less than 75 hours on it. It has started on the first or second pull since I've owned it, except for last week, when it wouldn't start at all. It will occasionally sputter, but then die. Gas is fresh. Air cleaner is clean. I changed the sparkplug. All with the same results. I haven't tried starting fluid. Any ideas before I have the dealer pick it up for $70 and wait for 2 weeks to get it fixed? Thanks for your help.