Calling all 1967 BBD 4116SA 2bbl Gurus
Hi all you BBD gurus!
My 273 2bbl (BBD 4116SA CAP) smells like it is running excessively rich.
Forgot to mention I'm at 5000 feet now.
I rebuilt the carb 1 year ago, I have put 1000 miles on it since. Drivability and acceleration are normal, idles OK, No stumbiling or bogging down. I may have done something wrong in the rebuild but I have successfully rebuilt carbs for years so who knows.
The carb was originally jetted for sea level with the "Standard" jets and after sitting for 4 years and with old gas in the tank I had the car smogged. At that time it passed and all the values were relatively low.
A few weeks later I rebuilt the carb and installed a set of "2 step lean" jets 120-297S, I smogged it this year, still passed, but the values were significantly higher, HC went from 379 to 1358 at 2500 RPM. CO% went from 0.57 to 3.02 at idle.
Just found some info that says too lean will result in a raised HC level (lean misfire)
I was going to see if going back to the sea level (standard) jets would fix the issue but the OE jets are trashed.
Bottom line is I could use a set of 120-310S jets if anyone has some. Or what the ID of the jet is and I can drill out my 310s
The Service manual lists "Standard" being 120-310S, "1 step lean" being 120-294S and "2 step lean" being 120-297S
Any thoughts would be greatly appreciated.
Hi all you BBD gurus!
My 273 2bbl (BBD 4116SA CAP) smells like it is running excessively rich.
Forgot to mention I'm at 5000 feet now.
I rebuilt the carb 1 year ago, I have put 1000 miles on it since. Drivability and acceleration are normal, idles OK, No stumbiling or bogging down. I may have done something wrong in the rebuild but I have successfully rebuilt carbs for years so who knows.
The carb was originally jetted for sea level with the "Standard" jets and after sitting for 4 years and with old gas in the tank I had the car smogged. At that time it passed and all the values were relatively low.
A few weeks later I rebuilt the carb and installed a set of "2 step lean" jets 120-297S, I smogged it this year, still passed, but the values were significantly higher, HC went from 379 to 1358 at 2500 RPM. CO% went from 0.57 to 3.02 at idle.
Just found some info that says too lean will result in a raised HC level (lean misfire)
I was going to see if going back to the sea level (standard) jets would fix the issue but the OE jets are trashed.
Bottom line is I could use a set of 120-310S jets if anyone has some. Or what the ID of the jet is and I can drill out my 310s
The Service manual lists "Standard" being 120-310S, "1 step lean" being 120-294S and "2 step lean" being 120-297S
Any thoughts would be greatly appreciated.