I replaced mine with a Banshee petcock. Perfect fit. Only issue was that I needed a longer fuel line because the Banshee petcock exits the side instead of the bottom. I paid $18 for it. Make sure you block off the vacuum port on the carb. I found these little rubber caps at ACE Hardware that work perfect. They are by the screws/bolts, and are for covering exposed bolt ends. The black size worked perfect. (the red size worked perfect to block of the oil injection at the carb too). They were like 10 cents.
2006 Honda TRX450ER
2008 Yamaha Raptor 250
1988 Suzuki LT80
1992 Suzuki LT80