Depends on which one it is.
Baby Bee might get to 13,000.
Black Widow can get to around 17,000.
The Venom & Killer Bee can get upwards of 20,000.
It mostly depends on reed material & age/wear, cylinder (porting & such), glow head (high compression vs regular), head gaskets, temperature of the air, humidity, phase of the moon, and whether or not you've saved 15% by switching to GEICO.
Sorry it's not more specific. I'm going to guess you're talking more about a Baby Bee or product engine, where the top end may be around 12,500 or 13,000. Larry should be able to give a better answer.