It only takes about 15 minutes and will make a world of difference in almost every case where a complete adjustment has been more than 5,000 miles past.
Here it is:
By the book, the slack at the lever should be 10-15mm, which is 0.4"- 0.6", or up to approx. 9/16" if you prefer to think of it that way. The cable end should be screwed in toward the lever as far as it will go up against the locking wheel and still let the locking wheel have enough threads to lock. This will give you enough room to make a fine-tuning for your particular feel.
At the far end of the cable wire itself; [under the center of the 3 left side covers] is where the most important adjustment is made. After loosening the outer locking nut, you use a narrow blade screwdriver & turn that screw counter-clockwise 3 turns or so. Then turn it inward slowly till you feel resistance become tangible. Back it off 1/4 turn and note that position so you can make sure it stays there. Then tighten up the locking nut again, without overtightening it.
At the bottom end of the cable shielding, where it goes into the case cover: The double nuts there are another key component. The top one locks the cable slack at the bottom end and really benefits from some blue loc-tite. That keeps it from vibrating loose and losing the adjustment.
In many case, the cable wire gets dry and you can use a little white lithium grease. You can't use WD-40 or other penetrating oils, since they penetrate and break down the metal as well as the shielding liner. Also lube the bottom end of the cable wire and the moving parts of the area behind.
By the book, the slack at the lever should be 10-15mm, which is 0.4"- 0.6", or up to approx. 9/16" if you prefer to think of it that way. The cable end should be screwed in toward the lever as far as it will go up against the locking wheel and still let the locking wheel have enough threads to lock. This will give you enough room to make a fine-tuning for your particular feel.
At the far end of the cable wire itself; [under the center of the 3 left side covers] is where the most important adjustment is made. After loosening the outer locking nut, you use a narrow blade screwdriver & turn that screw counter-clockwise 3 turns or so. Then turn it inward slowly till you feel resistance become tangible. Back it off 1/4 turn and note that position so you can make sure it stays there. Then tighten up the locking nut again, without overtightening it.
At the bottom end of the cable shielding, where it goes into the case cover: The double nuts there are another key component. The top one locks the cable slack at the bottom end and really benefits from some blue loc-tite. That keeps it from vibrating loose and losing the adjustment.
In many case, the cable wire gets dry and you can use a little white lithium grease. You can't use WD-40 or other penetrating oils, since they penetrate and break down the metal as well as the shielding liner. Also lube the bottom end of the cable wire and the moving parts of the area behind.
-----------------
But if clutch is adjusted fine, then it can be issue with master cylinder.
Is the master cyl piston returning all the way out with no pressure on the lever? I know with brake systems sometimes people dont leave enough slack in the lever adjustment and this causes issues with fluid exchange to the reservoir.
Oil should be 10W40 SF or SG grade. Anything else will cause the clutch to slip. There must be freeplay on the clutch cable (0.4-0.6in). Adjust handle bar clutch lever screw all the way out then adjust at gearbox end and revert to handle bar adjustment for fine adjustments. If this does not solve the problem take the clutch apart and measure driven plate thickness (3.12in minimum for the 1st plate and 2.62in minimum for the others)
Measure clutch spring free length. There are 2 sets (4 springs each). 0.97in minimum and 0.92in minimum respectively.
A slipping clutch is caused by incorrect friction, that is incorrect oil or insufficient pressure. Pressure is supplied by the springs on the discs and driven plates.
If the discs, driven plates or bucket is worn it will cause slippage.
If you pull in the clutch and it disengages but starts to re- engage after a short period you will need to replace the clutch master cylinder seals.
Measure clutch spring free length. There are 2 sets (4 springs each). 0.97in minimum and 0.92in minimum respectively.
A slipping clutch is caused by incorrect friction, that is incorrect oil or insufficient pressure. Pressure is supplied by the springs on the discs and driven plates.
If the discs, driven plates or bucket is worn it will cause slippage.
If you pull in the clutch and it disengages but starts to re- engage after a short period you will need to replace the clutch master cylinder seals.
-------------
Also other possibility can be air getting into the clutch system. Check to make sure all your fasteners are tight and that there is not a bad gasket in the reservoir or slave cylinder.
When bleeding the clutch system, make sure to put a loop in the drain tube above the bleeder valve to prevent air from getting back into the clutch system.
By the way, if your slave cylinder is leaking, you would notice the leak. Take a white paper towel and run along bottom of the slave cylinder area. If it's leaking bad enough to empty the hydraulic fluid (DOT 4) from the clutch reservoir, then it would get air into the clutch system.-----
When bleeding the clutch system, make sure to put a loop in the drain tube above the bleeder valve to prevent air from getting back into the clutch system.
By the way, if your slave cylinder is leaking, you would notice the leak. Take a white paper towel and run along bottom of the slave cylinder area. If it's leaking bad enough to empty the hydraulic fluid (DOT 4) from the clutch reservoir, then it would get air into the clutch system.-----
----------------
Are you sure all of the air is out of the system? motorcycle hydraulics are hard to bleed all the air out of the systems by using just the bleeder screws, as they do not put out enough volume to push out the air with the fluid.
--------------
--------------
most possible you can do to bleed air is :--
Bleed it both from the top down and from the bottom up. Also leaning the bike on its side to do the bleeding and breaking open the banjo fitting in the cylinder to bleed it.
If you have bleed it from the bottom up that is possible you did get all of the air out.If it was a straight up shot. what i mean is if their is a place for air to get trapped or caught it will not work. 
if you think it is fully bled then the only thing that comes to my mind s that the master cylinder or slave cylinder has lines or groves in the housing and the seals can not seal and it is letting air into the system.
you would need to replace the assembles to fix that
If you notice corrosion in the piston bore on the housing of slave cylinder.
having corrosion in the slave cylinder that is very possible to be the problem. If you know their is no air in the system. Then corrosion is the only reason I logically can think of the clutch to not work hydraulically.
