blown fuse

i have a 1976 kz900 i been having my main fuse blown 20 amp it will run for a while then blow a fuse

Check for shorts, clean connections, and make sure everything is getting good airflow.
My 750 kept blowing the main fuse and I couldn't figure out why. One day I was on the side of the road switching out the blown fuse and burned my hand on the ic ignitor. I repositioned it for better airflow and haven't blown a fuse since.

if you're running dyna coils make sure they are not grounding out on the mounts