So I'm 18 years old abd heading off to college this fall. I got my motorcycle liscense and picked up 1982 gl500 back in December of 2019 and bought it to have a bike in college as i have been riding dirt bike since i was a little kid and wanted a street bike. I completely rebuilt the motor. Only left in the crank and cam shaft. The bike now idles ok, just needs idle turned up. But when i drive it it wont go over 5k rpm and only runs on the left cylinder over 5k rpm. I've read some about the ATU possibly causing that. I've cleaned and rejetted the carbs. I've also tried 2 different sets of stock carbs. I need help. I've rebuilt a couple dirt bikes and tons of snowmobiles but have never had an engine give me troubles like this thing has. Thank you.