What effect, if any, would this have on the plane taking off?

I have a 1/4 scale Decathlon ARF that has the leading edge of the left wing about 1/4” forward of the right. I think the wing tube in the fuselage was installed askew at the factory. Would this be the reason it’s cartwheeling the moment the wing starts to fly?

I doubt it. You may want to measure each wing tip to fin TE and put an incidence meter on each wing tip. Very possible you have a wing warp or the fin is offset.

Thanks. Will do.

I agree with Speedracer. If the tube is out of alignment it may also be slightly high or low thus affecting wing incidence. Going through and measuring everything to make sure it is square is relatively easy and doesn't cost anything. You don't mention what engine or prop you have on the airplane. A big engine - prop combo can induce torque swing at takeoff. IF everything is in proper alignment then you may need more right thrust or just the proverbial bootful of rudder at take off.

Thanks mgnostic.