I'd like to add another data point to this forum. I bought my 2009 S40 a few weeks ago with 14,500 miles, and a clutch that slips above 30 mph. The clutch seemed like it was barely engaging from a stop, I could put the bike in 1st, release the clutch lever, and it wouldn't stall, but I could give it throttle and it would go.

I did not observe where the clutch release arm was adjusted to before I started the work. I opened the clutch cover, and took out the 45.5mm push rod, and put in the long 46.5mm push rod, based on the information I found in the first few pages of this thread. Buttoned everything up, and started the bike, and clutch would not engage at all. I shifted it into 1st, released the clutch lever, and bike sat idling and stationary, in 1st. I tried it in 2nd and same thing. So the clutch was keeping the engine and transmission separate constantly, and now it was worse than before.

I now observed that the clutch release arm was at the bottom mark. I opened up the clutch cover, and put in the short 44.5mm push rod. I closed it all up, and now the clutch release arm was pointing almost to the top mark. I started the bike up, put it in 1st, and as I released the clutch lever, I felt it begin to pull immediately. I took it out on a ride and it it felt like a new clutch.

As stated in the last few pages of this thread, check where you clutch release arm is pointing before you decide to change out the push rod for a different length. For me the clutch release arm was pointing to the bottom mark, and I changed it for a shorter push rod, and that completely fixed the issue.

As the clutch friction plates wear - the movable plate gets closer to the right side clutch cover.  At some point the adjustment is gone and the rod is too long to allow more adjustment.....and needs to be replaced with a shorter rod.