The Ford Barn

len47merc · 04-08-2014, 06:52 AM

In rebuilding a previously untouched 59 A-B found that the cylinders serviced by the right/passenger barrel of the carb were running much richer than the left, this after running the car for 1,000 miles+ on the rebuilt carb (i.e., not sure whether the rich deposits on these 4 cylinders were from pre or post-carb rebuild). On re-breakdown and analysis of all air-flow ports, jets, etc., all that can be found now that stands out between the two barrels is the right/passenger side idle jet adjusting screw is much more worn and rounded than the left. After carb rebuild the car idled smoothly and idle responded well to the 'one turn out, then 1/8 in until...' process. Can anyone weigh in on their experience with worn idle mixture adjusting screws producing smooth idle yet rich overall mixture. This vehicle is driven mainly around town and in rural areas at modest speeds (mostly < 45 mph).

I've had very good advice to check this after the motor rebuild and install is complete by an hour drive at speed (55 mph), shutdown and new plug check which I plan on doing, but would like some confirmation on this one issue before hitting the road. Thanks - Steve

Bruce Lancaster · 04-08-2014, 09:23 AM

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Look over the air bleeds in the affected side nozzle bar...2 tiny holes in front part of the bar, on each for idle and main path.
Then, one at a time, swap idle screws to opposite side, swap jets to opposite sides...if you have the good jet wrench all can be done without disassembly of main carb.

04-08-2014, 06:52 AM	#1
len47merc Junior Member Join Date: Dec 2013 Location: North Carolina, USA Posts: 21	59 A-B 94 Carb running rich in right/passenger barrell only In rebuilding a previously untouched 59 A-B found that the cylinders serviced by the right/passenger barrel of the carb were running much richer than the left, this after running the car for 1,000 miles+ on the rebuilt carb (i.e., not sure whether the rich deposits on these 4 cylinders were from pre or post-carb rebuild). On re-breakdown and analysis of all air-flow ports, jets, etc., all that can be found now that stands out between the two barrels is the right/passenger side idle jet adjusting screw is much more worn and rounded than the left. After carb rebuild the car idled smoothly and idle responded well to the 'one turn out, then 1/8 in until...' process. Can anyone weigh in on their experience with worn idle mixture adjusting screws producing smooth idle yet rich overall mixture. This vehicle is driven mainly around town and in rural areas at modest speeds (mostly < 45 mph). I've had very good advice to check this after the motor rebuild and install is complete by an hour drive at speed (55 mph), shutdown and new plug check which I plan on doing, but would like some confirmation on this one issue before hitting the road. Thanks - Steve

04-08-2014, 09:23 AM	#2
Bruce Lancaster Member Emeritus Join Date: May 2010 Location: Madison, NJ Posts: 5,230	Re: 59 A-B 94 Carb running rich in right/passenger barrell only Sponsored Links (Register now to hide all advertisements) Look over the air bleeds in the affected side nozzle bar...2 tiny holes in front part of the bar, on each for idle and main path. Then, one at a time, swap idle screws to opposite side, swap jets to opposite sides...if you have the good jet wrench all can be done without disassembly of main carb.