25 johnson comp ?

[m wright]

thinking of buying a 1978 25 hp johnson from an aquaint. he let me bring home for a check out. first thing , comp. test is 126# and 116#.less than 10%; is this normal for this outboard?

 

[JB]

Re: 25 johnson comp ?

Good numbers. If you give her a good decarb treatment they may come even closer.

 

[tashasdaddy]

Re: 25 johnson comp ?

agree. Decarb, take a can of seafoam put 3/4 of it in the gas tank, with only 1 gallon of premixed gas. put the rest in a spray bottle. start the engine, and let it come up to temperature. then remove plugs, and them some real good shot of seafoam into the cylinders, replace plugs, let sit 15 minutes. restart, and spray the rest of the seafoam into the carbs, so the the motor almost stalls, wait and repeat until the seafoam is gone.then take for a wide open spin. then put in new plugs, ad premixed gas to the tank, and take it for a wide open throttle spin. it is going to smoke like a house on fire, during this process.

afterwards compression.recheck