My Os .46 run great on my trainers. now it is on my fun star and is runs great on the ground but once i get in the air it runs fine for about 2 min and then it just bogs down and i have to keap it under 1/4 throttle or it will stall. could it be that the OS.46 is nearly inverted. Please help.

No, inverted isn't the problem, but something else is. It sounds to me like you have it too lean on the high-speed needle. The ability to run OK at low throttle settings, but not at full power, suggests a lean condition, or overheating (which could also come from being too lean). Did you ever overheat it in the past -- this can also cause a failure like the one that you described. Another possibility that I hesitate to mention is a peeled liner. Or it could be as simple as something may be wonky in your fuel delivery system (tank, vent, fuel lines).

Good luck