I have two 18HP Honda / 44" Fastrak mowers. Both have about 250hrs each. I bought them one month apart, 6 years ago. The first one I bought has never given me a bit of trouble. The second one has been going through fits of not starting intermittently for the past two years. I can mow with it for an hour, shut it off and it won't restart 30 minutes later. Sometimes it will run a day, sit for 3-5 days and won't start. When I say it won't restart, it cranks fine, fires, but will not run. I don't believe it is a safety switch issue. Any ideas?