diff --git a/resources/profiles/Prusa/filament/Prusa Generic ABS @MK4.json b/resources/profiles/Prusa/filament/Prusa Generic ABS @MK4.json
index c3e0a7c511..f25685fa9c 100644
--- a/resources/profiles/Prusa/filament/Prusa Generic ABS @MK4.json	
+++ b/resources/profiles/Prusa/filament/Prusa Generic ABS @MK4.json	
@@ -13,7 +13,7 @@
         "12"
     ],
     "filament_start_gcode": [
-        "; Filament gcode\nM900 K{if nozzle_diameter[0]==0.4}0.04{elsif nozzle_diameter[0]==0.25}0.1{elsif nozzle_diameter[0]==0.3}0.06{elsif nozzle_diameter[0]==0.35}0.05{elsif nozzle_diameter[0]==0.5}0.03{elsif nozzle_diameter[0]==0.6}0.02{elsif nozzle_diameter[0]==0.8}0.01{else}0{endif} ; Filament gcode\n\n{if printer_notes=~/.*PRINTER_MODEL_MK4IS.*/}\nM572 S{if nozzle_diameter[0]==0.4}0.02{elsif nozzle_diameter[0]==0.5}0.018{elsif nozzle_diameter[0]==0.6}0.012{elsif nozzle_diameter[0]==0.8}0.01{elsif nozzle_diameter[0]==0.25}0.09{elsif nozzle_diameter[0]==0.3}0.065{else}0{endif} ; Filament gcode\n{endif}\n\nM142 S40 ; set heatbreak target temp"
+        "; Filament gcode\nM900 K{if nozzle_diameter[0]==0.4}0.03{elsif nozzle_diameter[0]==0.25}0.1{elsif nozzle_diameter[0]==0.3}0.06{elsif nozzle_diameter[0]==0.35}0.05{elsif nozzle_diameter[0]==0.5}0.03{elsif nozzle_diameter[0]==0.6}0.02{elsif nozzle_diameter[0]==0.8}0.01{else}0{endif} ; Filament gcode\n\n{if printer_notes=~/.*PRINTER_MODEL_MK4IS.*/}\nM572 S{if nozzle_diameter[0]==0.4}0.02{elsif nozzle_diameter[0]==0.5}0.018{elsif nozzle_diameter[0]==0.6}0.012{elsif nozzle_diameter[0]==0.8}0.01{elsif nozzle_diameter[0]==0.25}0.09{elsif nozzle_diameter[0]==0.3}0.065{else}0{endif} ; Filament gcode\n{endif}\n\nM142 S40 ; set heatbreak target temp"
     ],
     "compatible_printers": [
       "Prusa MK4 0.4 nozzle"
diff --git a/resources/profiles/Prusa/filament/Prusa Generic ASA @MK4.json b/resources/profiles/Prusa/filament/Prusa Generic ASA @MK4.json
index c9bbbdc46a..14ee70e905 100644
--- a/resources/profiles/Prusa/filament/Prusa Generic ASA @MK4.json	
+++ b/resources/profiles/Prusa/filament/Prusa Generic ASA @MK4.json	
@@ -13,7 +13,7 @@
         "12"
     ],
     "filament_start_gcode": [
-        "; Filament gcode\nM900 K{if nozzle_diameter[0]==0.4}0.04{elsif nozzle_diameter[0]==0.25}0.1{elsif nozzle_diameter[0]==0.3}0.06{elsif nozzle_diameter[0]==0.35}0.05{elsif nozzle_diameter[0]==0.5}0.03{elsif nozzle_diameter[0]==0.6}0.02{elsif nozzle_diameter[0]==0.8}0.01{else}0{endif} ; Filament gcode\n\n{if printer_notes=~/.*PRINTER_MODEL_MK4IS.*/}\nM572 S{if nozzle_diameter[0]==0.4}0.02{elsif nozzle_diameter[0]==0.5}0.018{elsif nozzle_diameter[0]==0.6}0.012{elsif nozzle_diameter[0]==0.8}0.01{elsif nozzle_diameter[0]==0.25}0.09{elsif nozzle_diameter[0]==0.3}0.065{else}0{endif} ; Filament gcode\n{endif}\n\nM142 S40 ; set heatbreak target temp"
+        "; Filament gcode\nM900 K{if nozzle_diameter[0]==0.4}0.03{elsif nozzle_diameter[0]==0.25}0.1{elsif nozzle_diameter[0]==0.3}0.06{elsif nozzle_diameter[0]==0.35}0.05{elsif nozzle_diameter[0]==0.5}0.03{elsif nozzle_diameter[0]==0.6}0.02{elsif nozzle_diameter[0]==0.8}0.01{else}0{endif} ; Filament gcode\n\n{if printer_notes=~/.*PRINTER_MODEL_MK4IS.*/}\nM572 S{if nozzle_diameter[0]==0.4}0.02{elsif nozzle_diameter[0]==0.5}0.018{elsif nozzle_diameter[0]==0.6}0.012{elsif nozzle_diameter[0]==0.8}0.01{elsif nozzle_diameter[0]==0.25}0.09{elsif nozzle_diameter[0]==0.3}0.065{else}0{endif} ; Filament gcode\n{endif}\n\nM142 S40 ; set heatbreak target temp"
     ],
     "compatible_printers": [
       "Prusa MK4 0.4 nozzle"
diff --git a/resources/profiles/Prusa/filament/Prusa Generic PETG @MK4.json b/resources/profiles/Prusa/filament/Prusa Generic PETG @MK4.json
index 53159f3b18..095c574b1b 100644
--- a/resources/profiles/Prusa/filament/Prusa Generic PETG @MK4.json	
+++ b/resources/profiles/Prusa/filament/Prusa Generic PETG @MK4.json	
@@ -5,7 +5,7 @@
     "name": "Prusa Generic PETG @MK4",
     "from": "system",
     "instantiation": "true",
-    "inherits": "Prusa Generic PETG",
+    "inherits": "fdm_filament_pet",
     "reduce_fan_stop_start_freq": [
         "1"
     ],
@@ -39,6 +39,9 @@
     "filament_max_volumetric_speed": [
         "10"
     ],
+    "filament_start_gcode": [
+        "; filament start gcode\nM900 K{if nozzle_diameter[0]==0.4}0.035{elsif nozzle_diameter[0]==0.25}0.12{elsif nozzle_diameter[0]==0.3}0.09{elsif nozzle_diameter[0]==0.35}0.08{elsif nozzle_diameter[0]==0.6}0.04{elsif nozzle_diameter[0]==0.5}0.05{elsif nozzle_diameter[0]==0.8}0.02{else}0{endif} ; Filament gcode\n\n{if printer_notes=~/.*PRINTER_MODEL_MK4IS.*/}\nM572 S{if nozzle_diameter[0]==0.4}0.055{elsif nozzle_diameter[0]==0.5}0.042{elsif nozzle_diameter[0]==0.6}0.025{elsif nozzle_diameter[0]==0.8}0.018{elsif nozzle_diameter[0]==0.25}0.18{elsif nozzle_diameter[0]==0.3}0.1{else}0{endif} ; Filament gcode\n{endif}\n\nM142 S36 ; set heatbreak target temp"
+    ],
     "compatible_printers": [
       "Prusa MK4 0.4 nozzle"
     ]
diff --git a/resources/profiles/Prusa/filament/Prusa Generic PLA @MK4.json b/resources/profiles/Prusa/filament/Prusa Generic PLA @MK4.json
index db2c24136a..216b03a823 100644
--- a/resources/profiles/Prusa/filament/Prusa Generic PLA @MK4.json	
+++ b/resources/profiles/Prusa/filament/Prusa Generic PLA @MK4.json	
@@ -16,7 +16,7 @@
         "8"
     ],
     "filament_start_gcode": [
-        "; filament start gcode\nM900 K{if nozzle_diameter[0]==0.4}0.05{elsif nozzle_diameter[0]==0.25}0.14{elsif nozzle_diameter[0]==0.3}0.07{elsif nozzle_diameter[0]==0.35}0.06{elsif nozzle_diameter[0]==0.6}0.03{elsif nozzle_diameter[0]==0.5}0.035{elsif nozzle_diameter[0]==0.8}0.015{else}0{endif} ; Filament gcode\n\n{if printer_notes=~/.*PRINTER_MODEL_MK4IS.*/}\nM572 S{if nozzle_diameter[0]==0.4}0.038{elsif nozzle_diameter[0]==0.5}0.025{elsif nozzle_diameter[0]==0.6}0.02{elsif nozzle_diameter[0]==0.8}0.014{elsif nozzle_diameter[0]==0.25}0.12{elsif nozzle_diameter[0]==0.3}0.08{else}0{endif} ; Filament gcode\n{endif}\n\nM142 S36 ; set heatbreak target temp"
+        "; filament start gcode\nM900 K{if nozzle_diameter[0]==0.4}0.026{elsif nozzle_diameter[0]==0.25}0.14{elsif nozzle_diameter[0]==0.3}0.07{elsif nozzle_diameter[0]==0.35}0.06{elsif nozzle_diameter[0]==0.6}0.03{elsif nozzle_diameter[0]==0.5}0.035{elsif nozzle_diameter[0]==0.8}0.015{else}0{endif} ; Filament gcode\n\n{if printer_notes=~/.*PRINTER_MODEL_MK4IS.*/}\nM572 S{if nozzle_diameter[0]==0.4}0.038{elsif nozzle_diameter[0]==0.5}0.025{elsif nozzle_diameter[0]==0.6}0.02{elsif nozzle_diameter[0]==0.8}0.014{elsif nozzle_diameter[0]==0.25}0.12{elsif nozzle_diameter[0]==0.3}0.08{else}0{endif} ; Filament gcode\n{endif}\n\nM142 S36 ; set heatbreak target temp"
     ],
     "compatible_printers": [
       "Prusa MK4 0.4 nozzle"