Yeah if the bike has not been running for years, there is bound to be blockages in the carby jets and orifices due to stale fuel. Old fuel causes heaps of problems these days, especially premium because it goes stale pretty quickly. You really gotta be riding the bike almost once a week so the fuel doesnt go off in the bowl. It can actually grows a green algy stuff. I will never forget the time i stripped a set of XS750 carbs and they were full of a dark green algy growing inside them, it looked like the stuff you would see in a creek or fish pond. It was really really bad and smelt really strong and bad and the smell hung around for a few days. That was the worst one i had ever come across. Before Xmas i put a new head gasket on a Trident which had not been ridden for several months because of the head leak. Well after fixing that, the bike would not run on the middle cylinder so when i took the carbies off the middle one was all blocked up with some sort of white stuff from fuel that had gone off. Before that it was gutless and seemed to only do about 80km's but after cleaning it out it was much more like the rocket it should be like and was so much better when runnning on 3 cylinders.