Outboard troubleshooting Motor won't run at full power .has reached full power and runs great but then goes back to were it has loss of power again

SOURCE: 1974 60hp johnson outboard won't run on full throttle.

Carbs probably need to be cleaned and re-built. Common problem in outboards that havent been run in a while

SOURCE: 40hp 1987 yamaha outboard motor will run for 30-60

Sound like the fuel pump is not keeping up with the engine's demand. Check it out. Good luck. Hope this helps.

SOURCE: Motor spits and sputters

If it is old enough to have points then I would check them and make shure they are clean and gapped at .020. if that is noth the problem then it sounds like a fuel issue. Either a weak pump or a dirty carb.

SOURCE: outboard motor won't run under load

I have 1969 5hp Johnson. Starts and runs good, but will only push a 14ft row boat slow at low to medium rpm. When at higher rpm the the motor just revs up and the boat slows down to almost nothing just like it has seaweed around prop.Any help would be great.

SOURCE: Johnson Outboard Motor 175HP

Unplug the heat sensor and try it.