A popular upgrade is to fit 'smoothie' washers, not something I've done before but accessing the drag washers is a simple enough task. I've broken down the process and documented it below.
Next comes the metal washer. Make sure all of your metal washers are nice and smooth on both sides. If they feel rough or show signs of wear they are cheap to replace with original ones or smoother aftermarket ones.
Another replacement drag washer, grey side uppermost.