If at all possible you should 1st isolate if it's a fuel or an electrical problem, then you won't end up wasting a bunch of time doing work you don't need to.
Whenever there's a problem like what you described it's always a good idea to take a look at the spark plugs and see what the carbon residue looks like on the end of the plug. If it's white your possibly lean, if it's black your carb jetting may be too rich. If a plug(s) is soaked in fuel it may be a bad spark plug or issue with spark reaching that plug. If it's got spark then the carb(s) might be dumping too much fuel into the engine, that could be a stuck or misadjusted fuel float or a passage way in the carb being obstructed. If the needle was stuck in an open position that could also cause too much fuel in the combustion chamber and a wet spark plug.
While your checking the plugs make sure you've got spark from each spark plug wire. If you do have spark you can also check the coil(s) fairly easily with an Ohm meter to make sure it's putting out the proper spark - a service manual, the internet, or your local dealer should be able to tell you the correct rating. I had one of the coils go bad on my 1996 GSXR 750, I checked each of them with an Ohm meter (engine off) and it was obvious which one was bad.
A plugged fuel filter (possibly in the tank) can cause fuel starvation problems, also watch out for inline sock/screen filters that can slip down inside the fuel line and be completely unseen from the outside - some bikes have those.
That's some things to check.
