- Navigate to the "Gamedata" folder in your Stalker local files (Right click the game in your Steam library, click "Properties" and select "Browse local files").
- Open the "Config" folder.
- Open system.ltx with notepad.
- Find the line -
[inventory]
max_weight
= 60
Change it to whatever you like, i changed mine to 200.
- Save the notepad file and exit.

- Now open the "Creatures" folder which is also inside the config folder.
- Open actor.ltx with notepad.
- Find the line -
[actor]
max_item_mass
= 60
The value must be exactly the same as the previous number you just set for max_weight.

- Next find the line -
[actor_condition]
max_walk_weight
= 70
You must change this value to be greater than the previous two because this is how much you are allowed to carry before you are unable to move.
- Save the notepad and exit.

That's it.
Bye now.