The bike you are working on has a couple of way to adjust the clutch. Obviously the adjuster on the handlebars would be the first place but actually there is an adjustment on the other end of the cable that has a locking nut on it. You will need to loosen the nut that locks the cable and there should be another nut on the other side of the cable that you can tighten. As you tighten the nut it will take the free play out of the cable.
There is another adjustment on the inside of the clutch cover, it is on the clutch hub. The adjustment for this would be done by removing the clutch cover to access the clutch hub. On the outside of the hub there is an 12mm nut locking down a 6mm adjusting screw, the screw is adcually the first source of adjustment on initial assembly.
Let me give you the breakdown of how this works, your clutch mechanism has the hub adjustment, a ball, and a push rod that goes through the primary output shaft of the transmission. Then it goes to the actuating arm where your cable connects. The reason I'm telling you this is because often the ball in between the hub adjuster screw and the clutch push rod becomes welded to the push rod or it will actually start to come apart. When this happens your clutch adjustment goes away and you have no adjustment available through the cable or the clutch lever. Should this be your case I would recommend you take the clutch cover off, (be sure to drain the oil first), remove the six 10mm nuts securing the clutch hub, (this also holds the clutch springs in place), then you will have access to the push rod and the ball. You may have to tilt the bike over on the right side to get the push rod and ball to come out.
When you go to reassemble the clutch make sure all the adjusters are loose so you can adjust the clutch in the following sequence:
- Assemble the hub and secure the springs. You want to adjust the hub screw first. Gently turn the screw in until it contacts the ball, then back out the screw 1/4 turn. This prevents the ball from welding it's self to the ball and plunger.
- Install the clutch cover and the clutch cable all the way to the lever. You will first adjust the free play out at the base of the cable so you have maximum adjustment at the lever.
- Adjust the lever so you have 1/4 of free play at the lever.
This will give you a properly adjusted clutch that has lots of adjustment at both the handlebars and at the base of the cable.
Good Luck! This is a DIY job, you wont need to take the bike to the shop if you are able to do any routine maintenance. Should you have to remove the clutch cover you will need to replace the right side, (clutch cover), engine gasket. If you take it apart I would recommend replacing the ball if it has any signs or wear, it will be blotted, this is a very cheap item that can cause much grief.
Let me know if you need any further assistance.