1966 Crown Coupe, 2016 200 S AWD, 1962 Lark Daytona V8.
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17,255 Posts
First confirm correct ignition ignition timing. If you can just get it to barely 'ping' on hot acceleration, that is about the correct timing. This may be difficult to hear with a loud exhaust.
You can use a dial micrometer with a long stem in the #1 spark plug hole to determine exact TDC. Then make a mark on the timing cover to index TDC. Try 10° BTDC with an advance timing light first and go from there. Watch advance as you rev it with the vacuum advance both hooked up and disconnected. You want to see it swing to ~30°-40° BTDC total advance with the hose on and revved.
Make sure that you have the correct carburetor # on the engine. This should be stamped on the base casting. A Carter from a 360 or LeanBurn application would run lean and one from a 440 would run rich. Determine if you are too rich or too lean. 'Choking' to me means too rich. 'Starving for fuel'means too lean. You give conflicting symptoms. A puff of black exhaust smoke on acceleration may be from a rich condition. Carburetor 'pop-back' on acceleration may be from a lean condition. You have to determine which.
Spark plug tips might tell a story of fuel mixture (black=rich and white=lean) and must be the recommended Champion RJ-12YC for best results. Opening the throttle with the inrush of an air/fuel mixture may simply be 'blowing out the candles' if spark voltage is low or the spark plugs are either wrong or fouled.
Was this a rebuilt carb out of the box or did you rebuild it? The secondary air flap spring tension adjustment and the power metering jet rod adjustment is critical and must be in correct adjustment. Playing with the adjustments might make the situation better or worse, but that will tell you which way you have to go with the mixture to get it correct. When you do any adjustment, remember where you started from (how many turns) so you can put it back the way it was before if necessary.
You can use a dial micrometer with a long stem in the #1 spark plug hole to determine exact TDC. Then make a mark on the timing cover to index TDC. Try 10° BTDC with an advance timing light first and go from there. Watch advance as you rev it with the vacuum advance both hooked up and disconnected. You want to see it swing to ~30°-40° BTDC total advance with the hose on and revved.
Make sure that you have the correct carburetor # on the engine. This should be stamped on the base casting. A Carter from a 360 or LeanBurn application would run lean and one from a 440 would run rich. Determine if you are too rich or too lean. 'Choking' to me means too rich. 'Starving for fuel'means too lean. You give conflicting symptoms. A puff of black exhaust smoke on acceleration may be from a rich condition. Carburetor 'pop-back' on acceleration may be from a lean condition. You have to determine which.
Spark plug tips might tell a story of fuel mixture (black=rich and white=lean) and must be the recommended Champion RJ-12YC for best results. Opening the throttle with the inrush of an air/fuel mixture may simply be 'blowing out the candles' if spark voltage is low or the spark plugs are either wrong or fouled.
Was this a rebuilt carb out of the box or did you rebuild it? The secondary air flap spring tension adjustment and the power metering jet rod adjustment is critical and must be in correct adjustment. Playing with the adjustments might make the situation better or worse, but that will tell you which way you have to go with the mixture to get it correct. When you do any adjustment, remember where you started from (how many turns) so you can put it back the way it was before if necessary.