Have you removed the left cover, taken the inner worm out of the housing, cleaned, inspected, generously lubed it, reinstall?
How about the cable, Have you removed it, cleaned inspected and lubed it as well?
On reinstalling the cable route it with as few bends as possible, any bends should be as little as possible. On the metal sleeve around the cable at the case carefully straightening it a bit help too.
A well lubed cable and worm make the clutch easy to pull.
On the adjustment, I do things a bit different than the book. When It says to back out the worm adjuster I back it out several turns and spin it in and out a few times. This gives you a good feel for the amount of pressure it takes to spin just the adjuster. This is important because you need to know when the resistance just starts to increase.
Now with a good feel for it turn the adjuster in till you just feel an increase in pressure. This is the point that all the slack is taken up between the adjuster screw and the pressure plate. At this point you need to add a bit of slack back into the mechanism.
The book calls for 1/4 turn, I think that's a bit much. I use 1/6 of a turn, Easy to do, this is one flat of the lock nut. Once you get this done It gives you about as much movement of the pressure plate as you can get without slippage.
Now adjust the lever for about 1/8 to 1/4 inch free play.
This does make the lever be out close to fully out where the clutch engages but it reduces clutch drag to the minimum. Making finding neutral easier.
Leo