Black Oily carbon from prop hub

[needhelp22]

I have a 2002 Johnson 90 hp that has an black oily carbon discharge that comes out of the prop hub. I've learned from other blogs that it could be because I troll 100% of the time or that it runs too rich.

Is the oily discharge a big problem? What can I do to fix it if so?

When I initially start the motor it looses power frequently, similiar to a timming issue or missfire, accompanied with excessive exhaust. The frequency reduces trumendously after 5 minutes, but still happens occasionally.

Is this related to my problem above? If not what could it be?

 

[ezeke]

Re: Black Oily carbon from prop hub

It is not a big problem and it is fairly normal with trolling motors.

Running high quality synthetic oils with Carbon Guard or similar treatment will help as will making sure that the engine is always running at the correct temperature.

Try to take a short cruise at the end of your fishing trip.

Be sure to do a thorough de-carbon treatment once a year and be sure that the recirculation check valves are functioning properly afterwards.

More here: http://forums.iboats.com/showthread.php?t=207285

& http://forums.iboats.com/showthread.php?t=158076

 

[needhelp22]

Re: Black Oily carbon from prop hub

Thanks for the speedy responce. Good to hear the oily carbon is not abnormal. I just finished the de-carb 10 minutes ago. Seems to be running better already.

Not sure what a recirculation valve is? I'm new to the outboards.

 

[nightstalker]

Re: Black Oily carbon from prop hub

I have a 2002 Johnson 90 hp that has an black oily carbon discharge that comes out of the prop hub. I've learned from other blogs that it could be because I troll 100% of the time or that it runs too rich.

Is the oily discharge a big problem? What can I do to fix it if so?

When I initially start the motor it looses power frequently, similiar to a timming issue or missfire, accompanied with excessive exhaust. The frequency reduces trumendously after 5 minutes, but still happens occasionally.

Is this related to my problem above? If not what could it be?

I had the same problem whenever I trolled for a long period of time. I solved it by always running back to the ramp at full throttle whenever possible.
Nightstalker

 

[James R]

Re: Black Oily carbon from prop hub

Seems to be less of a problem with Penzoil Synthetic Blend.

 

[ezeke]

Re: Black Oily carbon from prop hub

It is less of a problem with Shell's Pennzoil Synthetic Blend. In fact, that was the first synthetic that I tried on my two stroke motors. It produced quite noticeably less fouling than the old OMC oil.

I found that generally the synthetic blend and full synthetic TC-W3 oils with higher flashpoints produced less fouling than the less refined oils.

 

[F_R]

Re: Black Oily carbon from prop hub

needhelp, consider this: That is the exhaust pipe. Carbon is a byproduct of combustion and goes out the exhaust. The oil that you put in the tank is partially burned (smoke), but most of it goes out the exhaust. So, "oily carbon" is very normal. Feel better?

 

[kenmyfam]

Re: Black Oily carbon from prop hub

I'm with the F_R response !!!

 

[needhelp22]

Re: Black Oily carbon from prop hub

Thanks for the info. Sounds like its not a problem. I guess I will be using Shell's Pennzoil Synthetic Blend next time.

 

[nightstalker]

Re: Black Oily carbon from prop hub

Thanks for the info. Sounds like its not a problem. I guess I will be using Shell's Pennzoil Synthetic Blend next time.

You won't be sorry!!!!!!!!!!!!!!!!!!!!!
Nightstalker