I bought a low wing sports arf and there is no right thrust built in and appears to be no down thrust either.

If the manufacturer did not build this into the plane, should I assume it is not needed?

Or should I assume someone in China did not do their homework?

You could guess one way or the other, or you could fly it and know for sure?

If this ARF uses a cowl, I would do the maiden and first few test flights without. That way, if you did need t change it, your cowl mounting screws and cut outs would be messed up/need adjusting.

Hi!
On most low winged airplanes no side or right thrust is needed.

A good starting point is 2 degrees Rt thrust, without it every time you pull up you will need to hold some right rudder, Depending on the power level and the prop you may reed to add a little more or less. I have had sport planes that HAD to have right thrust or they would not have enough rudder authority to overcome torque.

Symmetrical airfoils usually don't need down (or up) thrust if they are built square, otherwise some adjustments may be necessary to compensate for wing or stab not being 0-0.

Lifting airfoils on the kind of grossly overpowered airplanes we fly may benefit from some down thrust to minimize airspeed induced climbing or diving, adjust as needed but usually only 1-3 degrees. Powered sailplaned on the other hand may need at least 5 degrees down thrust. Done right it takes a lot of the workload off of the pilot and lets you be a better flyer.

D.H.