You could check for a weak spark by sticking the business end of the spark plug on the tip of your tongue then get someone to try to start the bike! If you **** and piss at the same time the plug is good.... If you just piss or **** or even just twitch uncontrollably then itís a weak spark and change the plug first then the coils!
I kid, I kid
My first thought wouldve been the choke!! i cant help a whole lot with this sorry! Just check the funcition of the choke and look at the cable that operates the choke.