Hi Guys,

need an advice..i'm facing a problem where one of my carbies it's not working well as it supposed,when i closed the A carburetor's mouth,pulled the cable plug 1&2 the engine is still running but vice versa on the carburetor B..so i can tell the engine is only running with carb B..but it runs worst

**carb A is for cylinder 1&2
**carb B is for cylinder 3&4

the symptoms that i'm facing:-
1. when idling,it produced a boxer sound
2. backfire at the carby and exhaust too

i've changed the gasket and also the position of the carbies,and yet only one that working fine which is carb B..it seems like the carb A is not feeding the engine with the fuel..

What is the problem?i'm totally have no idea..please shed some light..

Many Thanks.