I have a Saitek X-52 controller, and in some of the choppers, the factory Bell Jet Ranger, and most of the Hovercontrol freeware addons (412, etc) when I grab the collective and apply throttle, the engine decelerates, and the chopper never leaves the ground.

The exact same setup works just fine in FS9,  and for the Robinson, and some other freeware choppers.

Any ideas?  Thanks in advance

set to max realism across the board.

aaaah, THAT is where that is, prop RPM.  I have that one mapped as I have a pretty strong tendency to fly radials, Beavers to be exact.  Prop RPM is quite important.  Would that be relative to applied torque in a helicopter?

As is now, when I apply throttle, it almost sounds like a carberated car with a choke, applying gas when the choke is still on, and the engine "riches" out.  It spins up, then dies down as more throttle is applied.

I will try that tonight after the kids go to bed.

Dave Nailed it.  By assigning Prop/RPM to an axis or a rotary controller, this was the trick.  Here is what happened.  When you are in a fixed wing craft, the default settings are full rich/full pitch.  When you are in *some* rotorcraft, the pitch is set to 50%.  This isn't going to get you too far in a chopper.  Once this value was assigned to an axis, a dial on the throttle in my case, this worked much better.
The only caveat, is to be careful with that dial, if you accidentally dial it down in flight, bad bad things happen. 

Thanks everyone!

Noel,

If your problem is the heli wont lift off:  (In the default Bell) In the 2D cockpit click on the 'Collective' icon or press Shift+4. On the Collective you will see a ring marked Throttle with markings indicating Closed | | | Open. Use your mouse or press (Ctrl+F4) to set the throttle ring to Open. Check the 'Rotor/Pwr Turb-Percent RPM' gauge. When the pointers are 'in the green' your ready to fly.

It is not really necessary to assign joystick buttons or axis as, unlike an airplane, you normally leave the 'throttle'  open throughout the flight.  

If you wish to assign joystick control: Open the Setting>Controls window. Make the assignment(s) to the 'Propeller' event(s). If you already have joystick assignments for the 'Propeller RPM' control in airplanes with constant speed props the same assignments control the heli 'throttle'.

If your assigning buttons just assign one to a 'Propeller (Increase RPM....)' event and another to a 'Propeller (Decrease RPM......)' event. Move the 'Repeat' sliders to  the right some.

If you have a free axis (a rotary or slider) you assign it to the 'Propeller Axis' event. You may have to tic  'Reverse' so that the control direction feels right to you.

Dave