First thing I would do is to pull the carb and rebuild it (I say carb instead of carbs, not sure what engine you have since a stock '93 was a 650). Anyway, buy a mikuni kit: there is a fuel filter inside the carb that can get clogged up. Also, make sure the jets aren't clogged, and also replace all the gaskets and rebuild the fuel pump (replace the clear discs on the other side of the carb). Also make sure the needle and seat assembly is not plugged or stuck shut. And finally, blow out all the passages (hi and lo speed adjuster holes too) and clean them out.
And, while you have the carb off, check the reed valves too.
I'd also check your fuel selector switch to make sure it's not plugged, that's actually pretty common.
It could also be plugs and/or plug wires. You can cut the wires back and put new plug ends on.
