I recently bought a boat that has a 1975 25hp johnson outboard motor. Put in the water, cranked right up. Tried to go full throttle and it sounded like it skiped a gear and went back to mid throttle and it did this everytime I tried to go full throttle. I took apart the lower unit today just to check out everything and everything seem to be fine besides the oil in the lower unit was carmel color. Im not very experienced with boat motors or have ever done anything to a boat motor. Any advice please try to break it down where Ill understand. also should I clean the carb? I took the top spark plug out and it seemed dry. Thanks!!