Hey guys, I have a 283 stock engine with a holly 600 4 barrell on it and it is running extremely rich. I checked the main jets and they are .055 drill size hole. Do you think if I try a .050, it will lean up a bit? Choke seems to be Ok and the car runs good and does not miss, however it blackens the plugs. Any help will be appreciated.
That's not a real big jet. You got other problems, I think. Maybe the powervalve is leaking. Dumping a little fuel all the time. It should seal up completely when not in use. Float level too high? Pump pressure over 6? Bad gasket where the body fits the metering plate.?
I agree with the other responders, check the power valve. I have a 283 in our 49 truck with a 1850 (600) and I don't recall exactly what size is in the primary side but 6X, probably 62 or 64. My plugs, due to our ****ty CA gas look white, ever so slightly tan. I never had any 5X jets so I know they're not in there.
if you cannot correct with mentioned items check all flat surfaces by draw filing them flat besure to use quality gaskets.............
You may have blocked air bleeds as shown below. #1 is idle curcuit and cruz #2 is high speed or main jet. If either get blocked, a richer condition will result.
Just to clearify, this is done internally and not by restricting air bleeds. The OP may not know what your refering to.
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