Doh! Yes of course - smoke fitting is now plugged.

However, the plane itself is pretty messy on the outside too. Even if the black goo is blown out the exhaust - would you say it's making too much black goo?

The engine is running perfectly, very strong and also very reliable and steady idle. I also has a nice smooth feel when turning the hub or flipping the prob.

Would you say the the amount of residue is ground for lowering the oil contents (currently running 3.3% as prescribed, normal mixture is prescribed to 2.5%)?

Or should I lean it a bit (still on factory settings, 4 stroking quite a bit)?

Or should I live with it for a while longer?