Is it safe to plug a rear tire from a motorcycle?
Not with a regular car plug from the outside. Patch/plug from the inside. From the Dunlop website FAQ: Some punctures in motorcycle tires can be repaired if no other damage is present. Dunlop recommends only individual permanent plug-patch repairs of small tread area punctures from within the demounted tire by a qualified tire repair shop or motorcycle dealer. Never perform an exterior repair and never use an innertube as a substitute for a proper repair. Your bike should not exceed 50 mph for the first 24 hours after the repair and the repaired tire should never be used over 80 mph. Dunlop speed ratings are voided by repairs.
As a professional I have done it for myself, it all depends on where the hole is in the tire how, big the hole is and what kind of plug you use. It is not recommended to plug a motorcycle except in an emergency and you will not find someone to do it for you. As for it being safe, if done right it can last the life of the tire, on the other hand that plugged tire can kill you. So I would say if you have never done it before don't do it. Buy a new tire and be safe.
Plugging a puncture on a tubeless motorcycle tire is, at best, an emergency measure to get your bike somewhere where it can be properly repaired. DO NOT trust a plug any farther than you have to. Either patch the puncture properly, or replace the tire.
