I need your help, 1996 Yamaha 750 Virago carbs have been rebuilt valve have been checked I started out at two and a half turns out on the fuel air I can't get it to stop slightly backfiring through the mufflers only at idle I put in a stage 2 Kit on the carburetor with no improvement I'm going to try a thing of seafoam next but I'd love your thought process on this and when I did the carburetors I did a thorough job I've been doing them for a long time but this Yamaha has got me perplexed I'm generally a Honda Goldwing guy but I'm all around mechanic fix anything like you kind of obviously not as good but thanks in advance if you can help