I have a Jamara receiver but i can´t figure out how to connect the servos and speed control ( with BEC). I don´t know which way i should turn the connector, if the "ground" cable is up or down ( see picture)

EDIT: if I take a close look at the receiver can I see that the 4 upper pins are connected to each other.

If the 4 pins are connected togeter that would be the ground. Just make sure you put your servo ground to those pins.the middle should be +5 and the other end should be signal.

why don't you try different ways. If it works it's right if it doesn't try again.

Since the red (hot) wire is in the middle, you can't damage anything by plugging in the servos backwards, or so the legend goes.

I say this because on certain receivers I've used, when I plugged the battery in backwards it was a dead short, and the battery got HOT in short order... I definitely knew it was plugged in backwards. However, no real damage was done.

Go here.

http://www.balsapr.com/images/ediag.JPG

It has a diagram of one way that might work for you.\

-John