Here is a link to a video published by
Bike Bandit showing how to plug a tubeless motorcycle tire using one of the sticky-string tire plugging systems typically sold in auto accessory stores for around $10 (without the CO2 cartridges)- or two to three times that at motorcycle accessory stores, such as
Bike Bandit.
http://www.bikebandit.com/community/videos/how-to-plug-tubeless-motorcycle-tire