diff --git a/libraries/AP_Motors/AP_MotorsTri.cpp b/libraries/AP_Motors/AP_MotorsTri.cpp
index c9ad76b805..871a84d477 100644
--- a/libraries/AP_Motors/AP_MotorsTri.cpp
+++ b/libraries/AP_Motors/AP_MotorsTri.cpp
@@ -51,6 +51,8 @@ void AP_MotorsTri::init(motor_frame_class frame_class, motor_frame_type frame_ty
     // allow mapping of motor7
     add_motor_num(AP_MOTORS_CH_TRI_YAW);
 
+    SRV_Channels::set_angle(SRV_Channels::get_motor_function(AP_MOTORS_CH_TRI_YAW), _yaw_servo_angle_max_deg*100);
+
     // check for reverse tricopter
     if (frame_type == MOTOR_FRAME_TYPE_PLUSREV) {
         _pitch_reversed = true;
@@ -95,7 +97,7 @@ void AP_MotorsTri::output_to_motors()
             rc_write(AP_MOTORS_MOT_1, output_to_pwm(0));
             rc_write(AP_MOTORS_MOT_2, output_to_pwm(0));
             rc_write(AP_MOTORS_MOT_4, output_to_pwm(0));
-            rc_write(AP_MOTORS_CH_TRI_YAW, _yaw_servo->get_trim());
+            rc_write_angle(AP_MOTORS_CH_TRI_YAW, 0);
             break;
         case SpoolState::GROUND_IDLE:
             // sends output to motors when armed but not flying
@@ -105,7 +107,7 @@ void AP_MotorsTri::output_to_motors()
             rc_write(AP_MOTORS_MOT_1, output_to_pwm(_actuator[1]));
             rc_write(AP_MOTORS_MOT_2, output_to_pwm(_actuator[2]));
             rc_write(AP_MOTORS_MOT_4, output_to_pwm(_actuator[4]));
-            rc_write(AP_MOTORS_CH_TRI_YAW, _yaw_servo->get_trim());
+            rc_write_angle(AP_MOTORS_CH_TRI_YAW, 0);
             break;
         case SpoolState::SPOOLING_UP:
         case SpoolState::THROTTLE_UNLIMITED:
@@ -117,7 +119,7 @@ void AP_MotorsTri::output_to_motors()
             rc_write(AP_MOTORS_MOT_1, output_to_pwm(_actuator[1]));
             rc_write(AP_MOTORS_MOT_2, output_to_pwm(_actuator[2]));
             rc_write(AP_MOTORS_MOT_4, output_to_pwm(_actuator[4]));
-            rc_write(AP_MOTORS_CH_TRI_YAW, calc_yaw_radio_output(_pivot_angle, radians(_yaw_servo_angle_max_deg)));
+            rc_write_angle(AP_MOTORS_CH_TRI_YAW, degrees(_pivot_angle)*100);
             break;
     }
 }
@@ -154,6 +156,8 @@ void AP_MotorsTri::output_armed_stabilizing()
     float   rpy_high = 0.0f;            // highest motor value
     float   thr_adj;                    // the difference between the pilot's desired throttle and throttle_thrust_best_rpy
 
+    SRV_Channels::set_angle(SRV_Channels::get_motor_function(AP_MOTORS_CH_TRI_YAW), _yaw_servo_angle_max_deg*100);
+
     // sanity check YAW_SV_ANGLE parameter value to avoid divide by zero
     _yaw_servo_angle_max_deg = constrain_float(_yaw_servo_angle_max_deg, AP_MOTORS_TRI_SERVO_RANGE_DEG_MIN, AP_MOTORS_TRI_SERVO_RANGE_DEG_MAX);
 
@@ -310,24 +314,6 @@ void AP_MotorsTri::output_test_seq(uint8_t motor_seq, int16_t pwm)
     }
 }
 
-// calc_yaw_radio_output - calculate final radio output for yaw channel
-int16_t AP_MotorsTri::calc_yaw_radio_output(float yaw_input, float yaw_input_max)
-{
-    int16_t ret;
-
-    if (_yaw_servo->get_reversed()) {
-        yaw_input = -yaw_input;
-    }
-
-    if (yaw_input >= 0) {
-        ret = (_yaw_servo->get_trim() + (yaw_input / yaw_input_max * (_yaw_servo->get_output_max() - _yaw_servo->get_trim())));
-    } else {
-        ret = (_yaw_servo->get_trim() + (yaw_input / yaw_input_max * (_yaw_servo->get_trim() - _yaw_servo->get_output_min())));
-    }
-
-    return ret;
-}
-
 /*
   call vehicle supplied thrust compensation if set. This allows for
   vehicle specific thrust compensation for motor arrangements such as
@@ -358,7 +344,7 @@ void AP_MotorsTri::output_motor_mask(float thrust, uint8_t mask, float rudder_dt
     AP_MotorsMulticopter::output_motor_mask(thrust, mask, rudder_dt);
 
     // and override yaw servo
-    rc_write(AP_MOTORS_CH_TRI_YAW, _yaw_servo->get_trim());
+    rc_write_angle(AP_MOTORS_CH_TRI_YAW, 0);
 }
 
 float AP_MotorsTri::get_roll_factor(uint8_t i)
diff --git a/libraries/AP_Motors/AP_MotorsTri.h b/libraries/AP_Motors/AP_MotorsTri.h
index 494efa7878..523e2f91af 100644
--- a/libraries/AP_Motors/AP_MotorsTri.h
+++ b/libraries/AP_Motors/AP_MotorsTri.h
@@ -61,9 +61,6 @@ protected:
     // call vehicle supplied thrust compensation if set
     void                thrust_compensation(void) override;
     
-    // calc_yaw_radio_output - calculate final radio output for yaw channel
-    int16_t             calc_yaw_radio_output(float yaw_input, float yaw_input_max);        // calculate radio output for yaw servo, typically in range of 1100-1900
-
     // parameters
 
     SRV_Channel     *_yaw_servo; // yaw output channel