We were beating into 17 knots of winds, waves and current
yesterday. We were making 2.7 knots at about 3/4 throttle. We went up to full power to see what she would do (about 3.5 knots) and after about 30 minutes started to get a little smoke and black sooty exhaust water
. We also lost
some power without losing rpms. We trapped some of the exhaust
in a bottle to confirm that it was not oily and once we throttled back down the exhaust coming out was clean. We did a few tests over the next hour or so and when we revved up to full we would get the black soot. Our power was all over the place as well after that regardless of how much throttle we were giving her. Sometimes 3 knots and sometimes falling to 1 knot
or less without any change in wind
or waves etc.
After returning to the slip (we motored about 8 or 9 hours total) we talked to a few folks and checked online. We think it is likely we had fouled our prop, which also has a small amount of growth on it. We had not experienced that before and did not know how it felt to happen. We reversed getting into the slip and may have released some seaweed. When I dove in with a mask there was a handful of weed loosely on the shaft at the prop. I also noticed a bigger ball of the same type of weed floating in our slip which may have come off when we reversed in.
So ultimately, we plan to change/clean the air intake, polish our fuel
and proceed ahead.
Does anyone have experience with a problem like this? Do you think our engine
should be able to pull us along against wind
and waves at 3/4 throttle? (Until we started with diminished propulsion
we were making 2.5 knots) Do you think fouled prop could be a reason for our engine
to behave like this? Thanks in advance for your helpful advice.