I just installed a Dalton Industries clutch kit on my 03 KVF 650. I can feel it gripping the belt more. It also has a little higher engagement. It feels like it pulls a little harder through the low and mid. I haven't opened it up yet so I don't know if the top was hurt. I doubt it. Well worth the money. www.daltonindustries.com Check it out.

 

I didn't notice much, if any top end loss. of course I rarely if ever ride any place where I can open it up for long top end runs. The black secondary spring really helps for belt wear. And the dalton primary spring is real nice. The engagement is about halfway between the epi red spring and the stock spring. It make for a nice aggressive ride when you want it, yet lets you take off smoothly without have to feather the throttle as much as with the red spring.

For USA customers, Ritter Cycle is the Dalton distributer. http://www.rittercycle.com/

 

I just orderd a dalton spring yesterday and it should be here friday hope it works

 

The Dalton primary is the way to go.

 

The kit came with 2 springs. I imagine the secondary spring is close to the EPI black. I never checked rates tho. Whatever, it works.