BiRDY22b

its got the 4 barrell carby.. and i jus wanted to know what makes the secondary set of throats open becos it appears they arent opening at all... ?? ..

i also have a 82 mazda 626 and i joined the secondary throat with the throttle.. so they open together.. is there any way of doing that with the 4 barrell 12a carburettor ?? ...


any suggestions or help on getting the secondary throats to open would be great.. thanks

BiRDY22b

would be nice if people would respond instead of jus lookin at the thread .. =S

SparkienSuggah

The secondaries are opened by the large diaphram motor on the front side of the carb. They are permitted to open when you depress the throttle all the way down, a cam on the primaries will disengage the spring that aggressively holds the secondaries closed, and the vac motor can take over.
you know your secondaries arent opening when the engine wont post 4500rpm in gear.. any gear.
disconnect the vac motor and be sure its not ripped, siezed, properly connected etc. if the carb was rebuilt by a moron (or myself at 4am) then its possible the venturi/valve body gasket was installed upside-down. to check that take off the vac motor and spray a little carb cleaner into the port in the side of the carb where the motor breathes through.. if cleaner comes out from the bottom of the carb, the gasket is fubar, if not, check something else.
the throttle cable could also be loose.... not enough push means not enough go.