Brigg and stratton oppose twin 16 hp 401 707 start forever and when he turn he bug and refuse fuel, when I ask for power it bug, I replace spark plug, I clean carb, redooo the pump, clean gaz tank, and replace filter ,undoo the ignition coil, and clean for good ground, and still no power and no response with trottle... grrr can it be the intake plug up? seem like air fuel mix problemm this is a good engine no smoke and strong I like it but feel like burn it down thank you... help!!