i still have the socks, theres way less oil in them, The reason i couldnt figure it out, was because i took the first barrel sock of and nothing improved, so i didnt bother taking the rest of. yea its quite tight in the bay, i dunno why??, maybe diffrent manifolds. also is it common for the carbies 2 backfire a heap after tuning, its only when you back of the gas and slow down

just a thought...
possible needles seats not sealing? not a proper flow of fuel?
Might pay just just give em a check see

When the Weber sidedraught carbies backfire, it typically indicates a lean mixture condition. Twin carbs out of sync can also behave in a similar fashion.

Shouldn't be backfiring and certainly not after a tune. As said above could indicate lean mixture. If just at idle/light throttle opening may just need to open up the idle screws a little - really should have been right when leaving the mechanic who fiddled with it. If carbs are out of balance will be idling rough. Also check timing.

im having the exact same trouble, although with a dead stock a12. ive tried everything as well. its doing my head in as i have to drive up a mean ass hill to get home everyday.
under load it like - dedededededededededededeed, bang bang, deddededeeededddededededededed bang. and big loss of power. sometimes i manage to get home......

That sound is normally associated with carburetor synchronisation (or in your instance, severe lack of).

Balance your carbs.

Jetting issues are typically associated with popping, carb-backfiring and hesitation or 'bogging' sounds.

LOL.

Bogging sounds...... you carby people know what i mean!