For the first start of the day, my bike starts up on the front cylinder only. If I give it some throttle, I get a backfire out of the left pipe, and the rear cylinder comes to life. Every start for the remainder of the day is normal. Anyone experienced this problem?

Maybe your rear cylinder is a late riser or needs coffee to get it moving in the morning? Is your bike a real pain to start the first time of the day then?

not the expert, but to me sounds like the carb for ur second cylinder is leaky. not used to the one carb per cyl set up yet. Had a friend with a 79 f250 with a 390 in it. he had trouble starting it for the first time after a sit, turned out that he had a leaky 2nd carb (he was on a 4 barrel set up). had the same symptom of back fire meaning full mix was too rich...

what year is it and have u mixed with the fuel/air mix screws?