I always set up new engines w/o the governer. They mask tuning problems and the RL's run pretty bad surging and hunting with a rich engine.

Let me give you one thing to try, setup your RL on I1 in governor mode and I2 in limiter mode with a throttle curve about 10 points higher than you think you need in any position but the same head speed and see if it reacts better to limiter mode than governer. Its been my experience that some of the YS's just run better in limiter mode.