I never had a problem with thrust on 40 sized planes. When I got a poor 60 size kit that had the firewall with no thrust angle. The plane was pulling hard to the right(or was it left) and was very difficult to control on the ground. Brought it back to the shop and added some opposite thrust to the engine mounting. Made a world of difference. Still needed some rudder to keep it straight for the takeoff but no more than other planes. [8D]