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Carb too rich

832 Views 4 Replies 3 Participants Last post by  jeff swisher
, the engine is a 1972 250, carb is monojet bc from the original 66 230 engine. I made some major progress today, #1 the gasket between the carb and intake manifold needs to be thick enough to allow for decent air flow. I noticed the one that came with the rebuild kit was half the thickness of the original, luckily the original one was good enough to put back on. #2 The GAS cap was vented, so I plugged the vent so the fuel pump had to work harder to suck the gas, which slowed down the fuel flow. 3# the kit said to set the float level at 1inch 9/32, after many trial and error, I called my brother and he looked up a shop manual and the float needs to be set at 1inch 19/32. 4# I am using a propane torch to clean my spark plugs for each test. #5 install a pertronix HEI kit , part # 1162a, and also a flamethrower high performance coil. I bought mine off amazon. new plug wires are a must. #5 The timing should be set at 0. #6 install new manifold gasket, and gasket between intake and manifold. #7 new vacuum hoses. #8 make sure the choke is working properly, should be completely open when engine is warmed up. # carb has new needle & seat, and has been gone through carefully with carb cleaner and High pressure hose. # I switched fuel filter to a thicker brass type to slow down fuel pressure. I did all these things and the engine is running a lot better, plugs went from being char broiled, to slightly dusted.

I still have one strange thing going on, my mixture screw is only open by less than a quarter turn. When I tighten it down, the engine does not die, just keeps running fine. Does anyone have any ideas????

The idle screw has me wondering, the carb is from 1966, maybe somebody tighted it down too tight which widened the gap, I don't know, I will try a different mixture needle tomorrow, I actually have one.
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#2 The GAS cap was vented, so I plugged the vent so the fuel pump had to work harder to suck the gas, which slowed down the fuel flow.
Woof.
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