Full coverage or comprehensive motorcycle insurance is only really worth it if you're financing a new motorcycle and need to have the full coverage comprehensive insurance on the motorcycle.
If you own the motorcycle without payments and the bike is not worth all that much then it's not worth it to have full coverage motorcycle insurance.
That is if you can afford the loss of the motorcycle and could buy another motorcycle should your current motorcycle get totaled or stolen.
For used motorcycles that are not worth all that much then just liability motorcycle insurance would be good enough because full coverage motorcycle insurance would cost more per month and year.
You could just put that extra money into a savings account to replace your motorcycle without having to go through the insurance company.