Softer Coil Springs?

[Wedge]

I was just wondering, can I get softer springs for my Suntour fork or is there some other way of making the fork a little more plush?

 

I weigh 63kg and I find that I barely ever get the fork to even a third its travel and above that the fork is kinda rough and only really absorbs shock from big obstacles. My riding partner comes in at about 87kg and he gets the fork to travel all the way without being harsh.

 

Any help would be appreciated, otherwise it looks like an air fork is the only way.

 

Regards

Ruan