MY FRIEND HAS A JOHNSON 115 HP V4 MOTOR THAT SOUNDS LIKE IT IS SKIPPING A LITTLE BIT AT FULL THROTTLE. WIRES AND PLUGS HAVE BEEN REPLACED. SEVERAL TANKS OF GAS HAVE BEEN RUN THROUGH IT.IT ONLY DOES THIS AT HIGH SPEED.PROBLEM STARTED ABOUT 1 YR. AFTER PURCHASE.ANY SUGGESTIONS?
