Curvy backfiring on idle driving me mad.

Ive had no end of issues these last few weeks with my bike trying to get it on the road and mot'd.
At the moment im have a and issue with back firing.
firstly i was having a running on 1 cyclinder then i realised that i had lost the little washer off the needle in the carb. That replaced it now runs on both.
but it had a back fire issue.
i dont really know what is causing it.
ill give you a run down. cars completley clean, stripped and serviced. new irridium spark plugs, new air filter, new oil oil and filter.
carbs on tight and airbox on tight. mixture screw set at 2 1/4 turns on both. cant see and leaks/cracks in the exhaust and it runs ok when riding but the backfiring is loud, annoying and a bit embarressing to be honest.
please help.
i know the regulator is screwed as it keps draining my battery. i have one on the way. am i going mad as i jus want to be able to ride the bloody thing!

[flymo]

did you check the carb float levels when they were serviced? When were the valve clearances last checked?

Yeah the valves where done a month or so ago. and it wasn't backfiring till this time. The float levels where not adusted but the they are filling an not overflowing so I can only assume they are ok. Would a r/r cause backfire?

[embee]

If you know for sure the r/r is goosed then definitely get that sorted first, it's going to have to be sorted anyway. All sorts of electrical glitches could possibly come from a faulty r/r, depending on how it's failing.

Ok, I think i now have it sorted. New reg/rec which came with the wiring too short so had to do a bit of cuttin and soldering with the old one and half a turn on the mix screw on both carbs. Now running like a dream. Sounds healthy. First time it's had settled idle. Smile on my face is huge! Cheers guys