plugs carboned

hi stil having problems with my 85 maximx 700, *2and3 plug is a nice tan color but 1 and 4 are carboned up ive tried ajusting the mixture screw from 2.5 out right down to a quarter turn out.the carbs have been off the bike that many times ive lost count. float levels have been cheked yet again also the clear tube test and all seems to be ok. the plugs foal up almost right away and after a few miles of riding the plug gets that bad it stops sparking and i break down. ive just got the bike on the road finally after 4 long years of restoring it ,only got this
last problem to solve then i can enjoy the rest of the british summer riding. has anyone any suggestions as to what it could be, cheers,

 

I will try to answer this after dinner... gotta get home from work anyway

 

2 and 3 good, 1 and 4 bad has me thinking it's a coil.

 

had the same thought about the coil tried another one, dont know what bike it was off but still had same effect. does it make any difference which coil is used? and i,m not sure if the coil i used was any good. is it worth trying another one. does it have to be the same cc engine? any suggestions are appreciated, cheers.

 

i think you should be able to swap the plug wires and swap the "i'm not sure what they're called but whatever the wires that carry the signal from the TCI to your coils" wires - so you effectively have 1 and 4 running off the coil that normally runs 2 and 3 (and vice versa).

if the problem goes from 1 and 4 to 2 and 3, it's a pretty safe bet it's the coil. if the problem stays with 1 and 4, then it's a pretty safe bet your coils are A-OK