I have a 850 mechanical secondary carb on my 496 stroker. I had it out running today for the first time in about 2 months. Anyway the car ran fairly well, though there was an off idle hesitation. when i got back home and shut off the car, engine sort of snorted back through the carb (i am surmising). Anyway, when i went to restart it to put it back in the garage, it will not idle, it will run at a higher RPM....but if you take your foot out of the carb, it either immediately stalls or if you try to feather it back.....it wants to spit and backfire through the carb.....did I somehow pop the power valve or do something to the idle circuit? How can i fix this problem.....very frustrated!

bump.....anyone?

check float levels. if on the high side when eng hot gas expands and flood out eng.just went through similar problem with all this hot weather we been getting.

Look for a vacuum line or cap popped off.

Then maybe a power valve

bad gas gas goes bad in days somtimes . we did a experiment this winter with 4 cups of gas .one with out anything 3 with different dry gas . the one with startron lasted the longest the one with out anything had water in it in 7 days . JUST a thought !

hi
you may have blowen the power valve ?

how old is the carb , most newer ones have a blow out protection device .

first try tighting the fuel bowel screws a little and see if that helps any , dont overtighten !

and see that all vaccum ports are caped also .

prob something simple you just have to find it !

maby just a speck of dirt in one needle valve allowing fuell to flood out idle speed .