Since this bike is pretty old now,as far as basics go,i would be taking a look at the timing belts.You mentioned hard accel. is good,so plenty of fuel is getting to carbs.,and you have good spark. When i did my t.belts on my '94SE at 111,000 the right side one came off the gears without touching the tensioner. Before changing them,mine was doing a pretty good stumble on take off,as if still cold with not enough choke. Let us know what you find.