Steinar

I have a Futaba 9C transmitter with a R149DP receiver and a Y401 gyro in my heli. Lately i have had to give left trim on the rudder in order to kep the heli straight. The read light on the gyro is supposed to light continously vhen the rudder signal from the radio is "in center". That was how it was in the beginning. Now i must trim aproximately 36 "points" to the left in order to get continous light from the gyro and a stable and non-drifting heli. Sub-trim is zero. This sems to worsen almost by every day. I vill run out of trim in a couple weeks if this continues. What can i do with this?