Black soot exhaust tips

[acam37]

We are still very early in our engine break-in. (0320E2G 160hp carbureted) we have about 3hrs in the air and about an hour on the ground. Following the Lycomong break-in procedure for channel chrome bore cylinders. We are still running full rich 75% power at 4000ft. The CHT's are still averaging 370-390 degrees but have dropped from around 400 since the first flight. I guess my question is; is black soot in the exhaust tips which I understand is caused by running excessively rich mixture, normal or is it a sign of improper break-in or a major malfunction? We can't lean the engine because of the still high CHT's.

 

[airguy]

That's a normal result of running rich.

 

[N941WR]

That's a normal result of running rich.

Correct!

Keep running at full power and full rich until you get to 10 hours. Once you start learning it, your exhaust will turn grey.

 

[acam37]

Good deal. I was hoping this is normal during break-in. I just hope those CHT's continue to drop to more normal readings.