RCU Forums - ZDZ 40 carb trumpet?

Hi Mike, I have 2 questions for you. I have a used ZDZ 40 RV that I bought and was told it had a "few gallons" of run time. The engine runs great although I believe it is still running rich. It ran so good that I left the needles were they were set by the previous owner thinking it still needed breaking in. I just ordered a carb trumpet from you all in hopes that it will help keep the carb from spitting as much in my fuse, Will this help? Also, I'm using Mobil 2 T racing oil at 40:1 and am getting alot of spitting fuel/oil(black goo) out of the muffler and on the airplane. Should I start to lean this engine out now and is the mess normal? I've put a couple more gallons through it. Thanks in advance (7250 rpms with 20/8 NX prop)