[Eljaro]

I did take both exhaust systems off again and back on, sealing the slip on sidepipes to headerpipes with a special exhaust silicone sealant. I also made myself new special exhaust gaskets with only the vertical holes. All tightened up and no leaks as far as I can see.
But the backfiring on deceleration just does not go away. Whenever the throtle plates go shut backfiring occurs. The only way to get it reduced is if I set the idle say at 1300 rpm instead of 700-800.
I think I have jetting problem here, because it backfires from both sides no matter what.
The timing ist set 20º at idle, 38º max advance.
I also consistently find a pool of gasoline inside the carb throats several minutes after stopping the engine when it has run hot.
Help needed here before I start to tear everything down. It is a pitty, because otherwise the engine runs incredibly good. But the backfiring makes me go crazy.
Could it be a leak somewhere between the carbs and the intake? Or between the intake and the heads ? Or too rich an idle mixture ? I really do not know what is going on any more.
HEEEELP !!!!!!!!!!!