rick stopped by today with his 1970 big block corvette, he had purchased recently, its got a 750 cfm vacuum secondary demon carburetor , on the stock 4 barrel intake , and it was running like crap, I checked his timing and fuel pressure then noticed the accelerator pumps and squirters were not functional,obviously some passage or ports clogged so out comes the carb cleaner with the long spray nozzle,and I started looking for defective or bent linkage, so I adjusted the nut on the spring loaded lever that controls the plunger stroke on the accelerator pump,and got zero change,so I removed the 4 idle adjustment screws each one at a time and used the straw on the spray nozzle to squirt cleaner into each needle seat under pressure then re set the needle air valves at out one turn, then squirted about 1/4 of the can into each float bowl thru the side sight port after temporarily removing the glass site plugs, then I removed the front squirter and sprayed carb clearer into that opening then replaced that squirted and reset the carbs front and rear float levels
then I power squirted the 4 front and four rear air bleed openings to remove varnish and crud.from the 4 boosters, the result was the car started running significantly better and the accelerator pump and boosters started flowing fuel correctly, when you notice the accelerator pumps and squirters don,t work and the pump arm on the accelerator pump is functional, you more than likely are dealing with clogged internal passages, or very low fuel levels or pressure so you check each so the first steps to see it you can clear that with spray carb cleaner, yes you may need to disassemble and clean and rebuild the carb with new gaskets but its surprising how ofter a good dose of carb spray in all the little orifices can solve thise tyope of problem as its just varnish build up
then I power squirted the 4 front and four rear air bleed openings to remove varnish and crud.from the 4 boosters, the result was the car started running significantly better and the accelerator pump and boosters started flowing fuel correctly, when you notice the accelerator pumps and squirters don,t work and the pump arm on the accelerator pump is functional, you more than likely are dealing with clogged internal passages, or very low fuel levels or pressure so you check each so the first steps to see it you can clear that with spray carb cleaner, yes you may need to disassemble and clean and rebuild the carb with new gaskets but its surprising how ofter a good dose of carb spray in all the little orifices can solve thise tyope of problem as its just varnish build up
