Small Engines (Lawn Mowers, etc.): Echo PB-403T wont start, echo pb, incorrect fuel

Question
I have an Echo PB-403T and I can not get it to start.I have replaced the Coil, spark plug, and fuel to no avail. I am at a loss now. Please help. I do get spark at the plug. Thanks
Ken

Answer
Numerous conditions may cause this problem. Spark plug, incorrect fuel mixture, poor gas quality, dirty air filter, spark arrest, or exhaust carboned up or blocked. A dirty carb or one in need of a rebuild, dirty fuel filter in the tank on the end of the suction line to the carb. As you see it can be a long list.     Tom