Tom, My kid and I have been running a small 4 cycle Mercury for 2 years now. I did go thru about 6 months of agony of poor performance. I then found that the gas line PROVIDED with the motor was dissolving due to the ethynol in the gas. THIS WAS A NIGHTMARE!!!
So, when you get the motor, throw away the silver color fuel line and go get HEAVY, black fuel line.
That is all.....thanks.