Why does my plane keep banking to the left

[Aviator 1]

Hey everyone, Does anyone know why in flight sim the airplane during flight always wants to bank left, if i left the plane flying on a straight heading off autopilot and left the plane to carry on that course the plane will actually starting doing circles. I have tried trims and everything. The same thing happens if its a single engine or a 777. This is really annoying. any advice how to solve it ?

[chopper_nut]

I presume that you've calibrated your controllers?

[scaber]

More fuel in the left wing tank - or maybe you're using all your fuel from the right tank?