www.iFourWinns.com

I started my boat on the muffs yesterday and noticed the water coming from the motor appeared to have a dark sediment. I noticed this on my white concrete driveway. Didn't think much of it until I went to drain the block and the water that drained from it also appeared to have a dark sediment. It looked like carbon from exhaust or brake dust mixed in with the water.

I have it at the dealer for winterization and 20 hr check. I told them to check it out but want to have at least an idea of what if anything might be wrong. I have never seen that before any thoughts on what it might be?

And for you wise arses, I know boats don't have brakes but the discharge looks like the water you see on the driveway after you wash the wheels on your car.

The motor is a raw water cooled Volvo 8.1 Gi

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2008 Horizon 260 VP 8.1 Gi

There was a post quite similar recently; the black sediment is an oxide of iron, magnetite, that forms under water; it's normal, it's the active "ingredient" in a lode stone, the original compass!

Graham