Mayflash Adapter Vibration Not Working

[sylow]

I hope its ok if i ask here without opening a new thread. I used to play with an USB-XboxController, but it felt kind of wrong for me So i decided to buy the Mayflash USB Adapter for the original GC-Controller.

Everything is fine now except for the Rumble Effect. It is much too weak ingame, and it seems it makes no difference which Option i choose (Constant/Ramp/Sine) in Controller Configuration. Changing the Output-Level doesnt help either.The funny thing is if i test the rumble, it is much stronger.

Every help would be appreciated!