So this summer I bought a boat with a 1975 25hp Johnson on it. At first it wouldn't start but through some trial and error we discovered a condenser was bad. We replaced both for god measure since the motor hadn't been run for a few years. After we changed it out it started right up. Then the next problem was discovered. It would rev to max rpms. I tried to adjust the throttle and fuel mixture. Nothing would idle it down. Does it sound like the carb needs to be rebuilt?