There is no insurance co. providing global cover for vehicles. You can, and in many countries you must, have third party insurance. You can't insure your own bike against damage.
EU: Green Card system. Some countries bordering the EU participate in this scheme. It's compulsory for non-EU reg vehicles, but the crazy situation is that it is almost unobtainable in most countries. Depending on your entry point you may be able to get it at the border post. If you want it in advance look for the advert on this site by Knopf Tours. In GR, TR and I you can try the local AA offices. Worked for me in TR in 1989.
Iran, TR and Balkan countries: buy it at the border.
South America: now compulsory in many countries and apparently enforced. Go to http://abgefahren.info
and contact Klaus & Claudia for assistance.