seems strange to go for an exhaust to fix a firing problem lol
Think you misread my comment.
I want to fix the firing problem before I order my exhaust.
Seperate altogether but pointing out I'm wary of spending big on the full exhaust system only to have to spend big on the engine if I can't fix it. One thing at a time.
a quick look at the bike before work i managed to fire the bike up and pull each plug cap off and only number 3 came off without the bike idle being effected. so 2 and 3 on the same coil but only 3 was effected.
then swapped cap 3 onto spark plug two and fired it up, again, pulling it off dropped the idle. couldnt get to try lead 2 on spark plug 3 as it wouldnt reach (dont have time to take things apart before work to make it reah) but im guessing it wouldnt have done a thing.
so as you say, coil appears to be okay. and im guessing by the fact i put the lead and cap from 3 which wasnt running onto two which was, that rules out the caps or leads being at fault either.
next step clean the carbs? strip them off the bike or carb cleaner into the intake while its running?
i did drain the 4 bowls the other day and there was plenty of small bits of debris in each bowl. but didnt remove the bowls or the carbs at all.