I hate to keep adding to this, but in case somebody glances at it..
I scraped some shite off of my stock jet; and despite the haynes manual saying it's a size 47, the one I pulled out was...80.
I'd say that's quite a bit of a difference. Obviously the 50 was waaaaaaay too lean.
So, in conclusion, to the other 4 people on the face of the earth that own NVTs - check your physical jet, not the manual.
Cheers.