Why is my motorcycle making that noise?

I have a 1981 yamaha 1100 xs. This morning i was riding it to work and and it was fine. Halfway through my ride, i was on the freeway and my bike starts losing power. I manage to make it to work which is just off the freeway and when i stop, my bike is idling just under 1k rpms and it dies. After work the same exact thing happens except that i made it home. when it started to lose power it sounded almost like a lawnmower engine. I had to really get on the throttle to keep it going. It kinda felt like it was shaking a little bit. which i'm sure isn't normal. i put it in the 2nd choke setting and it seemed okay to get me home. I'm not a motorcycle mechanic obviously so if anyone has had this problem and has the solution would be a great help. thanks in advance