These are the repair rules:
http://www.dunloptires.com/care/repair.html
Care & Maintenance — Tire Repair
Tire repair
Any puncture or injury to a tire's tread area obviously affects performance and safety. Proper repair is critical. The puncture must be repaired on both the inside and the outside of the tire. Because all parts of a tire are engineered to function as a single unit, any repair must take that into consideration. Only small, straight-through 3/16" diameter or less punctures in the tread area may be repairable, if no secondary damage has occurred.
NOTE: A tire repair can be properly made only if the tire is removed from the rim; a thorough internal inspection is carried out; and the repair is made from the inside out. A repair must fill and seal the injury, i.e. vulcanized plug and patch. Only specially trained Technicians are qualified to repair a tire. Do not attempt to repair it yourself.
Dunlop Safety Advisory, Speed Rated Tires: Repaired tires must not be used in excess of posted speed limits, in race or other competition. Speed Ratings are not valid for repaired, re-treaded, under-inflated or overloaded, excessively worn, damaged or altered tires.
http://www.dunlopmotorcycle.com/infocenter_tiretips.asp?id=13
Some punctures in motorcycle tires may be repaired.
Dunlop recommends only permanent plug-patch repairs of small (maximum 1/4-inch diameter) tread area punctures from within the dismounted tire by a qualified tire repair shop or motorcycle dealer. Never perform an exterior repair and never use an inner tube as a substitute for a proper repair. Speed should not exceed 50 mph for the first 24 hours after repair and the repaired tire should never be used over 75 mph. Check inflation pressure after tire cools for at least three (3) hours following run-in, or sooner if air loss is suspected.
No form of temporary repair should be attempted because secondary damage caused by a penetrating object may not be detected and tire or tube deflation may occur at a later date.
Dunlop does not recommend the use of liquid sealants. These are a form of temporary repair, and they may adversely affect ply material and mask secondary damage caused by a penetrating object. Reliance upon sealants can result in sudden tire failure and accident.