Gary,

No I did not add any right thrust and it did not seem to need any, the OS 91 was perfectly 5 inches from the firewall as the suggest, I did crash and destroy mine today, had a flame out and tried to land in a cross wind and then got into a tailwind and stalled it, tip stalled right into the ground total loss, I have one on order though, this time I think I will add an onboard glow for low end as I think this time it flooded and caused the dead stick, or I my lower the stock mount and mount the engine right side up.