diff --git a/ROMFS/px4fmu_common/init.d/4009_qav250 b/ROMFS/px4fmu_common/init.d/4009_qav250
index 8baabce331..a3ce6d0f6b 100644
--- a/ROMFS/px4fmu_common/init.d/4009_qav250
+++ b/ROMFS/px4fmu_common/init.d/4009_qav250
@@ -30,7 +30,5 @@ then
 	param set PWM_MIN 1075
 	param set MPC_THR_MIN 0.06
 	param set MPC_MANTHR_MIN 0.06
-	param set MC_ROLLRATE_MAX 1000.0
-	param set MC_PITCHRATE_MAX 1000.0
-	param set MC_YAWRATE_MAX 400.0
+	param set CBRK_IO_SAFETY 22027
 fi
diff --git a/ROMFS/px4fmu_common/init.d/4050_generic_250 b/ROMFS/px4fmu_common/init.d/4050_generic_250
index c1cf12f56b..b806ed5446 100644
--- a/ROMFS/px4fmu_common/init.d/4050_generic_250
+++ b/ROMFS/px4fmu_common/init.d/4050_generic_250
@@ -1,6 +1,6 @@
 #!nsh
 #
-# @name generic_250
+# @name Generic 250 Racer
 #
 # @type Quadrotor x
 #
@@ -34,4 +34,5 @@ then
 	param set MC_PITCHRATE_MAX 1000.0
 	param set MC_YAWRATE_MAX 400.0
 	param set ATT_BIAS_MAX 0.0
+	param set CBRK_IO_SAFETY 22027
 fi
diff --git a/ROMFS/px4fmu_common/init.d/rc.mc_defaults b/ROMFS/px4fmu_common/init.d/rc.mc_defaults
index 1080121618..eb103b9614 100644
--- a/ROMFS/px4fmu_common/init.d/rc.mc_defaults
+++ b/ROMFS/px4fmu_common/init.d/rc.mc_defaults
@@ -17,20 +17,6 @@ then
 	param set PWM_MAX 1950
 fi
 
-# Transitional support: ensure suitable PWM min/max param values
-if param compare PWM_MIN 1000
-then
-	param set PWM_MIN 1075
-fi
-if param compare PWM_MAX 2000
-then
-	param set PWM_MAX 1950
-fi
-if param compare PWM_DISARMED 0
-then
-	param set PWM_DISARMED 900
-fi
-
 # set environment variables (!= parameters)
 set PWM_RATE 400
 # tell the mixer to use parameters for these instead
diff --git a/ROMFS/px4fmu_common/init.d/rcS b/ROMFS/px4fmu_common/init.d/rcS
index 626d43da63..378cbba170 100644
--- a/ROMFS/px4fmu_common/init.d/rcS
+++ b/ROMFS/px4fmu_common/init.d/rcS
@@ -540,6 +540,12 @@ then
 		fi
 	fi
 
+	# Transitional support: Disable safety on all Pixracer boards
+	if ver hwcmp PX4FMU_V4
+	then
+		param set CBRK_IO_SAFETY 22027
+	fi
+
 	#
 	# UAVCAN
 	#