Shawn, the same thing happened to me on one of my x's. I just went down to the auto parts store and found the next size up drain plug and tap. Re-drilled it to the appropriate size and re tapped it. Filled it back up with oil (twice) and let it drain out. Just don't go to big with the new plug. There is not a lot of material around the threads in that area of the case, so if you go to big your screwed. If it seeps on you wrap the plug with a little Teflon tape to get it to seal.
YAMAHA 450 HYBRID
85 350X- RED
85 350x -BLACK
86 350x-WHITE (with Goki)
85 250r
83 atc 70
84 atc 70
84 atc 110
09 yfz 450
2006 Arctic Cat Prowler
RZR XP 900