Hi Pop,
A simple tweak you could make to alter the yaw effect under said circumstances is to alter the engine datum points in the aircraft.cfg file.
If you reduce the separation distances (values 2.5 and -2.5) then the yaw will also decrease.
[GeneralEngineData]
engine_type = 1
Engine.0 = -35.8, -2.5, -0.1
Engine.1 = -35.8, 2.5, -0.1
fuel_flow_scalar = 1.0
min_throttle_limit = 0
There are probably other ways to achieve same result but this may be the easiest.