Jimmy, don't think it would hurt the injectors. Do you have a inline water seperator or filter under the cowl on right side of motor. If it does it should have a screw on clear plastic bowl. If it does remove and clean that. It's going to catch any trash before it gets to injectors. That SeaFoam should help cut that oil. I suspect previous owner mixed his own oil and gas and probably overdid it. And if you used the old line on boat it had residue in it. That fresh gas is going to cut that out and pick it up. It should burn most of it out pretty quick. I would run it good a time or two then I would install a new set of plugs. Just don't panic yet