caliber28
New Member
I have a Yanmar 2GM20 in my Caliber 28. I just took the boat out of dry dock in Chicago and ran it about 5 miles on motor only to its dock. I noticed a black film in the exhaust water at higher rpms. At lower rpms, moving at about 4 knots, there was no black film. Starting at 4.3 knots, there was film.
The engine starts fine. There are no unusual engine noises. The thermostat housing was replaced early in the winter when the coolant froze and popped a freeze plug.
I'm open to suggestions as to what the issue might be or where to look.
Thanks.
The engine starts fine. There are no unusual engine noises. The thermostat housing was replaced early in the winter when the coolant froze and popped a freeze plug.
I'm open to suggestions as to what the issue might be or where to look.
Thanks.