Originally Posted by BADBOOH
I have never heard of a spark plug blowing off, could be a bad sign. I don't believe 24:1 is the proper oil fuel mixture for an unbroke in motor. I go 40:1 for the first gallon then 32:1 after. Personal opinion. For some reason (may relate to your situation) when I position my fuel filter right side up my engine floods. Causes me to have to turn the motor over pedaling. This is hard work and takes close to 10 to 15 minutes to unflood the motor. Might help.
You should rethink your advice on fuel mix. A 40:1 ratio is a little light on oil for break in. We suggest a 24:1 mix for break in then after a couple of gallons move DOWN to a 32:1mix.
The larger number represents the gasoline, the smaller number the oil. In other words if you have 32 ounces of gas, you'll want to mix in 1 oz. of oil for a 32:1 ratio. Suggesting a 40:1 mix for break in is not good advice. The engine needs more oil than that when new.
In addition, the position of the fuel filter, unless you have it installed backwards has no effect on the way the engine runs. It sounds like you have a float problem or a incorrectly adjusted carburetor.