I recently purchased a 553 F series with 1700 hours. The only problem I noticed is it would emit white smoke occassionally. I used it for about an hour yesterday, I turned it off for about an hour, started it for about 3-4 minutes, turned it off and now it won't start. It turns over but that's it. I tried spraying a small amount of ether in the aircleaner but that hasn't done anything. Just prior to using it I did change the oil filter, air filter, and fuel filter. Any ideas?