Greyish looking substance coming from motor prop exhaust.

[ajohnson035]

I have a 94' Johnson 2 stroke 15hp there is a grayish looking substance coming from the motor prop exhaust hole when the motor is running hooked up to the water hose on the stand. Is this normal or is something wrong. The motor seems to run fine I had some fuel problems earlier so I rebuilt the carb and it runs fine just the stuff coming out of the prop hole concerns me. Thanks for your help. l

 

[tashasdaddy]

Re: Greyish looking substance coming from motor prop exhaust.

for insurance, i would check the lower unit fluid. but most likely it is left over exhaust deposits, and unburnt fuel it the exhaust housing. it would not hurt to do a decarb on your motor, and get rid of the excess carbon build up. it is like exlax for your motor.

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