Well so far I've noticed this engine is pretty poor quality compared to what I've owned before, so I wouldn't be surprised by a leaking gasket, and I'll test for that I get a chance.
As for the jet size, I actually did disassemble the carbon for general cleaning, and the jet is clear. I did however notice it was a lot smaller that what I remember. A very small opening. I was going to drill it a fraction bigger, but my drill press won't hold such a small drill piece.
I'll keep you updated