K1' has it pegged.
Just be careful not to spring it to stiffly, as most web based selection tools or charts will guide you to do.
Be sure to properly determine the spacer length to use, re the resultant installed preload, and correct L is not as simple as OEM spring + stock spacer = new spring + new spacer.
Increased oil level is usually a good strategy as well.
My rc51 forks in standard trim do not feel as good as my old standard forks with upgraded springs and oil. I haven't had a play with any settings on the rc51 forks yet and know a service, spring/shim change and setup would benefit greatly. I'm just saying the easiest route is springs and oil change for your standard forks is best value.