Here is a collection of notes from past posts regarding slave cylinder rebuild.
I ordered all three orings from my local dealer.
SM5 Clutch
As Doc said, only the lever is adjustable. While your clutch plates may well need replacement (there is a new clutch pack with an extra plate and a new oil nozzle available). If you are not experiencing any slipping, the clutch may still be serviceable for a while. The Spyder clutch is reknowned for engaging at the very end of the throw. There is no free play, and the hydraulic clutch engages over a very short distance. If you replace the clutch plates and discs, use part number 420281930 for an SM5. The SE has a different part number.
Change and Bleed the clutch fluid. Rebuild slave if necessary.
Clutch Slave Cylinder Rebuild
Page 05 Picture in the diagrams on the replacement parts at Cheapcycleparts.com
Diaphragm Cover
Orings – #10, #11, #13
p/n 420431441
p/n 420431301
p/n 420631892
Look up 2013 -5 service bulletin in the forum
I'm guessing that your slavecylinder has failed. This is a recurring problem that is being investigated. You will have to replace the slave piston & O-rings, and the slave bushing (cylinder) and O-rings. Cost of parts is about $80 if it is out of warranty. You will recognize the problem by discolored clutch fluid, due the the aluminum that is sluffed off the slavecylinder as it wears, and the deterioration of the O-rings. Be sure to thoroughly flush the clutch system when you do the work. If the clutch fluid is clear, the first place I would look is warped clutch plates, as Lamont said. There is a newly revised clutch pack available, with steel plates and 5 plates/discs. Be sure they order the one for the SM...the SE clutch kit is different. Time to see your dealer.
There is not a service bulletin addressing this problem as yet, but BRP should be making techs aware soon...possibly via notification on WebBoss. If you have an SM5 Spyder, especially one nearing the 20,000 mile range, and you have seen dirty clutch fluid, a rebuild would be in order before complete failure occurs. If you merely replaced the O-rings during a rebuild, you should do the job again, and replace the piston and bushing, too.