Wow, what a discovery, ay?

This is one for the experts, as my experience with the 2.0 is pretty limited. However, my racing friend spoke about how they used to weld those jet ports shut. That, of course, would involve removing the head and sending it out to have that done. Most everyone I have heard talk about these jet valves find them worthless. My vote would be to take the head off and see what you've got going on. Wait and see what the forum pros have to say. And look around your area to see if there is someone who CAN weld them shut.

But it seems to answer your question about smoking, doesn't it?

I can offer replacement jet valves should you decide to keep them intact...I have a 2.0 head I won't be using and could take them off. Eliminating them seems the best way to go, though...for the reasons you just discovered.