I have an old White Bros. R-4 slip on, bought it new in 2002. Took the spark arrestor out years ago, decided to put one back in recently because cops in CA are crackin down on stuff like that. They probably don't make it for yours either anymore, I found a guy on ebay selling them. I'd start there, check every day. Or go to Rocky Mountain ATV site, they have a lot of Pro Circuit Spark arrestors and baffles.
White Bros. R-4 slip-on.
White Bros CDI Box
No lid on airbox, holes with filters.
14-tooth front sprocket.
Pro Armor skid plate and heel guards.
Renthal handle bars.