that carb is ol school i have the same carb on my 49cc mini bike from 4 yrs ago..
So the "latest carb technology from BoyGoFast" is at least 4 years old. Good to know. The thread name was somewhat sarcastic, and sort of came from the fact that every picture of a NT carb I had seen had an intake tube and mine didn't. It seems that few people around here have been toying with the 48cc like myself.
So, back to the topic of main jets. I got some 5mm Dellorto main jets from dellortodirect.com, and was foolish not to measure my jet before hand. My 48cc BGF's HUAZHONG labeled carb with 13mm bore and NT labeled air filter housing evidently has a 4mm main jet.
The 4mm jets are even harder to find out there so it seems the solder-and-drill method will be put into use very soon.
I have another kit from BGF purchased earlier this year, which is a 66cc that I haven't installed yet because I need a mountain bike for a container. Just for fun, I pulled apart the carb in that kit (which looks like all the pictures in the NT carb tuning thread and has an intake tube). The BGF 66cc carb does appear to have a 5mm jet, but the Dellorto 5mm jet would only screw in 1 and 1/4 turns before stopping. So there's a difference in pitch or something!
I guess I will be selling some Dellorto 5mm jets on eBay soon.
So, Steve, when you got the range of jets, were they Dellorto 5mm? And did they fit properly? Or if anyone else with aftermarket jet experience could chime in, I'd appreciate it.
I think the biggest lesson I've learned is there's so much gosh darned variance in the sizing of these carbs and components, it's hardly worth the trouble of trying to find and buy proper jets. Maybe it's a BGF thing, maybe it's a HT thing, who knows.