Decarb..is this normal?

[mscott327]

I have a 2000 Yamaha 115 2 stroke motor. I've been having an issue with my tow vehicle so I haven't been out in a couple of months. Before the issue with the tow vehicle, I did a complete tune up and decarb on the motor (yearly Maintenance) I added seafoam to the gas tank to stabilize the fuel since the boat has been sitting. I've been cranking the boat every week or so to make sure I keep it running smooth, but I've noticed that since I added the seafoam to the fuel, I now see liquid carbon coming out of the exhaust every time I crank the boat in the driveway. The liquid is definitely liquid carbon coming from the exhaust by the prop. The carbon runs down the skeg. Is this normal since I added the seafoam? I had somewhere between 10-20 gallons in the boat when I added the seafoam. I added approximately 5-6 ounces of seafoam.

[jigger]

It might not be carbon coming from the engine. What it could be is condensation building up in the exhaust. Which is running out of the exhast and picking up a little soot on the way out. While the engine is running put your hand by the exhast port and see if it getting damp.

[KJS]

It is normal on my Johnson when running it on muffs.

[itwonder]

I would be better to let the motor sit than crank it up in the driveway every week. The reason is that running in your driveway, the motor is not under load and will be unable to get up to normal operating temperature, which is necessary to completely drive moisture out of the motor. Running that way will encourage condensation to form inside the motor, which may cause problems down the road. Just wait until you can get it in the water. Then run it hard and the black stuff should be gone.

[TSylivant]

Thats normal for my Johnson 200 oceanrunner when you run it on muffs. Its only exhaust soot. I too have to crank mine up in the winter when its not in use for about 2 months. That Johnson hates to sit idle

[brisboats]

Normal, lots of stuff gets loosen up from the midsection and will drool soot at the skeg until you run it out hard in the water.

Brian

[mscott327]

Thanks for the replies! I can't wait to get it back in the water. The spring dolphin run is almost here!!