Nose to tail bounce tells me your main rotor RPM is too low. You want to crank it up.
As for your slow yaw rate and 401 ---
Problem sounds like poor setup on your GY401. I looked back through a whole bunch of my past GY401 setup posts, here is one that you should be able to use to get your heli doing what you wish it to do:
Mechanically, things are simple. With the servo centered at neutral, the TR pitch slider is centered in its travel range. The servo arm is vertical. Adjust the pushrod as needed.
The pushrod supports need to be adjusted on the tail boom so that the pushrod has as straight a shot as possible from the servo to the bellcrank that runs the pitch slider, and so that the pushrod moves as freely as it can.
-----Set up your gain controls so that the 401 initializes in HH mode, this is a MUST, to always start the 401 in HH mode.
The 401's red LED will be on solid if you do this correctly. If it's blinking slowly, you didn't start up in HH mode. Fix that.
Your gyro's gain lead has to be plugged into channel 5 of your receiver to work correctly.
If your transmitter has REVolution Mixing and/or ACCeleration Mixing, DISABLE THEM, or dial them to ZERO.
-----ATVs -- the rudder channel ATV (Endpoint) settings on your transmitter are set at 100%. The ATV (Endpoint) setting will eventually be used to set the desired yaw rate (piro rate), and nothing else.
Set your RUDDER TRIM in ALL FLIGHT MODES to NEUTRAL. Don't touch the rudder trim tab again. Leave it at neutral in all flight modes. NEVER adjust the rudder trim AFTER you have initialized the gyro in HH mode.
To do so will confuse the gyro and it won't work correctly.
-----Set the TRAVEL LIMIT on the gyro to 100% for starters.
Set the DELAY on the gyro to ZERO. DELAY is used with slow servos to fine tune the gyro response.
The TRAVEL LIMIT adjustment is used to keep your TR servo linkage from mechanically binding at full rudder command. With the 401, you can't adjust the left and right full travel limits individually, the final travel limit setting is a compromise.
The following steps work best if you switch to rate/normal mode so that the servo follows the stick commands and returns to neutral when you let go of the rudder stick.
Pick a hole on the tail rotor servo arm that will allow you to achieve the following conditions:1.
TRAVEL LIMIT adjustment ends up as close as possible to 100%, at least no less than 100% without the pitch slider coming up against a mechanical stop at full left/right command.2.
The servo arm moves at least +/- 45 degrees from neutral for full left and right rudder command.
At this point, you've got at least +/-45 degrees of servo travel from neutral, the TRAVEL LIMIT setting is near 100%, but not less than 100%. Your pitch slider is centered at neutral, the servo arm is vertical at neutral, your rudder ATV (Endpoint) settings are at 100%, and DELAY is set to ZERO. Your gyro initializes in HH mode every time you start up your radio system.
Your rudder stick causes the boom mounted TR pushrod to move FORWARD for RIGHT rudder. The GYRO direction switch (REV/NOR) is set so that if you pick the heli up and turn the nose to the LEFT, the boom-mounted TR pushrod moves forward. This gets the rudder stick and the gyro acting in the proper direction.
The DS switch on the gyro is ON if you have a digital servo.
-----Turn on your radio and make sure the 401 initializes in HH mode.
After it does, switch to Normal/rate mode, fire up your heli, and bring it to a hover. If the heli wants to yaw left or right at hover, land, and ADJUST the mechanical linkage until the heli will hover in rate/normal mode without wanting its nose to go left or right.
Recheck and fine tune the TRAVEL LIMIT adjustment so that you don't get mechanical binding, if you had to adjust the linkage at all.
Switch back to HH mode. Reinitialize the gyro.
Start with your gain setting around 65%. Fly the heli and adjust the gain setting as required for your heli.
Adjust gain by flying the heli in fast forward flight. Increase the gain until the tail of the begins to oscillate in flight, then decrease the gain until the oscillation just goes away.
-----If you find that you want a FASTER piro rate, INCREASE the RUDDER ATV (Endpoint) value. If you find that you want a SLOWER piro rate, DECREASE the RUDDER ATV (Endpoint) value.
This should take you a long way towards getting your gyro to work well, and your heli to fly as it was intended to fly.
* Making the World Better -- One Helicopter at a time! *