View Full Version : engine question

07-30-2006, 09:18 PM
I recently purchased a 2001 Mobius from a private individual with 296 hours on it. After putting 6 hours on it, I've been really happy with it. No problems, great performance, and lots of fun!

I have noticed something that has me a little concerned though. After each trip out, there is a light black residue on and below the waterline in the stern. It comes up the side of the boat some, but fades to the bow of the boat. It's not aweful but is clearly visible on a yellow boat. I need to check and see if it's oily or sooty, but have not ... it does wash off very easily with soap and water, so I would tend to say that it's not oily. It has happened on two different lakes so I don't think it's just dirty lake water.

I immediately thought, oh crap it's burning oil but the oil level checks good and there is no visible smoke at idle, during acceleration or at other speeds. I have not cranked it out of the water to see if I see smoke.

So ... what's the internet diagnosis, guys?? What would you suggest other than keeping a close eye on oil usage which I would do anyways?


07-30-2006, 11:32 PM
Boat exhaust. Had it on my 05 until I went with an FAE (do a search). you are fine.


07-31-2006, 02:27 AM
All three inboard boats that I've owned have had the same thing around the exhaust outlets on the stern. It's normal.

07-31-2006, 09:59 AM
Happens to every engine not just boats I should know my truck is white after about 4 days it gets a little dark above the tail pipe. Does it in the outback and every other boat I've owned.


wakeboard dad
07-31-2006, 12:45 PM
I get the same thing on my '04 LSV. Not to worry.

07-31-2006, 10:27 PM
Thanks, all. I guess it shows up more on my boat than others I've seen because of color, etc ... plus it's mine so I'm paying closer attention to little things like this.