The carbs and their inability to deal with all the altitudes was always a problem. An airbox is a good idea to make CV carbs work. They are susceptible to float height problems. They do not deal well bouncing around in high altitude either. I do not know the cure to that. Left me flooded at about 13,000ft. I also had periodic problems with hard starting and flame outs. It would just run out of gas in windy conditions. My fuel pump would run the battery down trying to get the vacuum pump to fill the bowls. A common fix was a low pressure electric pump off a early 90's carburated R6. You need a relay.