i got some off of ebay, they were balls bearings i think. here's some on sale
REAR AXLE BEARINGS & SEALS YAMAHA BLASTER 88-02 YFS200 : eBay Motors (item 250460273501 end time Mar-04-10 12:43:39 PST)
yup don't forget to drill a hole for a grease zerk on the carrier so you can just hit it with a grease gun
i was saying drill a hole in the middle of the actual carrier, that way you can grease it with a grease gun instead of having to pull the axle out to do it. not required, just something to make your life easier down the road. but you don't actually have to drill any holes to replace the bearings