running rich? or lean
#3
RE: running rich? or lean
There is ALWAYS going to be some soot in the tailpipe, especially if you have a properly functioning choke. Don't go by that.
Warm the car up and take it for a light drive then shut it off and pull a plug. Too rich and the plug will be dark brown or black and sooty. Too lean and it will be white (or damaged from detonation). A light tan color is ideal.
Another quicker method is to warm the engine up, put a towel behind a tailpipe and then smell it. If it smells like gas, it's running rich. Not as accurate, but it'll give you a quick indication.
Warm the car up and take it for a light drive then shut it off and pull a plug. Too rich and the plug will be dark brown or black and sooty. Too lean and it will be white (or damaged from detonation). A light tan color is ideal.
Another quicker method is to warm the engine up, put a towel behind a tailpipe and then smell it. If it smells like gas, it's running rich. Not as accurate, but it'll give you a quick indication.
#5
RE: running rich? or lean
im pretty sure its running too rich theres a strong gas smell when its running but theres no leaks, and its too hard to take a plug out for that. i have to lift the engine a little to change the plugs
#8
RE: running rich? or lean
Do you have the proper calibration kit? If not, you need it. The carb instructions give you great directions on how to properly tune the carb, but you need the proper rods and jets to actually tune it.
#10
RE: running rich? or lean
If it's a stock 390BB then 750cfm is rather big. It can be tuned to work, but since most aftermarket carbs come factory calibrated for performance applications, a 750 will be set quite a bit differently than what you need for a mostly stock engine.