1945 vs bbs

Hmmmm. It's unusual to have to open an idle circuit up on a stock eng. in good condition.
Most carbs had plenty of enrichment "in the bag" to allow owners/techs to compensate
for small vacuum leaks,worn intake valve/guide clearance, etc. , since final idle "jetting"
was done w/ the mix screws. However, i suppose a combination of alky'd fuel, worn
engine, and a fine buildup of scale on the idle jet could've combined to create that
condition. Your buddy's engine was a '69?carb would've been a Holly 1920 stock,
totally different carb than the 1945, but you didn't mention if the eng./carb were
the orig's. Good of you to fix him up.
As I see it, there's no reason not to stick w/ the 1945, and rejetting the main
circuit when the eng. is under load & cruising at speed, is more critical to drivability
and longevity.Running lean is not good.
A final note on fuel. The new alky'd fuel is causing problems, even in the cars
designed to run on them! If the owners let the cars sit idle too long, slime starts to
develop in the tank,and actually doesn't go away w/ a fresh tankfull. repeated long
idle periods cause an accumulation of sludge that results in a tow to the shop, esp.
E85 cars. We just had to drain & clear a 2yr. old fuel system& replaced the pump,
NOT under warr. not cheap! Add to that a friend discovered a local station owner
was letting his buddy dump waste from cleaning paint guns etc. into his tanks!:wack: Buying fuel from/near a marina may be an option for some &
worth checking out, hope we have been helpful 74/6 !