My 1996 Triumph Thunderbird Sport had historical starting problems when I bought it , it had sat in a French barn for three years. So I pulled out the carbs and serviced them no joy ,then looked at the electrics new coils ,leads and plugs still no joy . Finally I found the problem no compression due to valve clearances couldn't get a feller gauge in four of the gaps .The bike has only done 36k but I made the school boy error of not checking the basics -air - fuel - spark - compression Hope it helps someone scratching their heads at the end of their tether Take care ride safe
@Crouchy If you start a new thread here, someone should be along to help you out. https://www.thetriumphforum.com/forums/technical-help.19/