hay all im using the futaba 6exhp tx. on the throttle hold settings it only lets me go to 50% not 75 or 100 is there a way to over ride this.

Throttle hold is typically used for gas/nitro power helis for doing autorotations, which keeps the engine just above an idle. It allows the pilot full use of the collective without the throttle being active.

I use throttle hold for my T-Rex like an off/on switch. I use it when carrying my heli to the flight and after a flight so the helit doesn't accidentally spool up if I hit the throttle during the transport.

I set it for -2.

You are confusing throttle hold with setting up throttle curves to keep your head speed constant.