What is curious about the Bee in question is why did it have hot starts to begin with? Hot starts are the number one cause of warpage and bearing failures.

Usually a hot start (at least from what I have seen) is typically operator error.

1) Fuel lines not purged of air, when turbine goes to fuel ramp (After starting on gas), it doesn't detect an increase in RPM, so the ECU (ICS) increases the pump pulse width which increase fuel output, by the time the fuel reaches the turbine there is way too much pump output and viola... you have a flame thrower.[X(]

2) Attempts of purging the air resulting in wetting down the combustion chamber with excess fuel. Be careful with that test the pump option, things can get real wet in a hurry [X(]

3) Too much start gas, I have seen some guys who like to "pour the coals" to the start gas because they think it should be starting quicker, you need to sit back and relax, the turbine will spool up in due time, too much start gas can result in localized heating once again resulting in a warp / rub situation. I now use a gauge on my propane tank and maintain the pressure to the turbine during the start sequence, you can hear the propane burner, monitor the temperature, and adjust the propane valve as required to ensure an uneventful start up.

4) Batteries - I think the charge condition is the number one possible source for issues when starting.