Topic: '79 CB650 Clutch Adjustment

[Pinhead]

After the modifications and extra horsepower that I've got out of my engine, my clutch seems to not be strong enough. If I cram WOT around 4k rpm, the clutch will let loose. I'm assuming it's never been adjusted in its 39,000 mile life. This is what my Haynes manual says:

In common with brake pad wear, clutch wear and the resultant necessary adjustment depends on operating conditions and the sytle of riding. Adjust the clutch, when necessary, as follows.

Check the clutch free play at the ball-end of the handlebar lever. The lever should move 10 - 20 mm (3/8 - 3/4 in) before the clutch begins to lift. If the free play is incorrect, the cable may be adjusted by means of the adjuster screws at both ends of the cable. The lower adjuster is used for coarse adjustments and the upper adjuster for finer running adjustments. If the upper adjuster threads project more than 8mm (0.3 in) from the lever stock, there is some adnger of the adjuster breaking out of the stock boss. To prevent this adjustment be made at the clutch housing. Slacken the lower cable adjuster locknut and, using the adjuster nut, obain maximum free play. Remove the clutch housing central inspection cap, and slacken the clutch release arm locknut which is now visible. Turn the adjuster screw clockwise until a slight resistance is fellt. From this position, turn the adjusting screw anticlockwise 3/4 of a turn, and retighten the locknut. Refit the inspection cap. Use the cable lower adjuster nut, adjust the cable until there is 10 - 20 mm (3/8 - 3/4 in) of free play at the ball end of the clutch lever. Retighten the lower adjuster locknut. Any further fine running adjustment can now be made at the upper cable adjuster at the handlebar lever.

I don't really want to tear my entire clutch assembly apart, though I wouldn't mind having a little stronger springs...  Is this the best way of adjusting the clutch? Is there some other way that will give me a little more grab than stock?

[eurban]

There really aren't any clutch adjustments that will compensate for the engine overpowering the clamping force/friction potentional of the clutch pack.  However, if your clutch cable is badly out of adjustment (too tight) it could keep the pack from completely clamping down and thus allow some slip.  You should always make the adjustment at the "clutch release arm" first, followed by a free play adjustment at the cables lower adjuster.  Fine tune it at the upper adjuster making sure that you don't have to unthread it too far out of the lever body. . . . If your clutch is slipping, make sure that you are not using an automotive type oil in your bike with friction modifiers!  Your clutch friction discs, plates, and springs might also be worn reducing the holding power of the clutch. If none of these things are the case, then your next step would probably be to install stiffer springs.  Not sure what options are out there for the 650 however.

[Ibsen]

You can get a Barnett spring kit:

http://www.barnettclutches.com/products/clutch_plates_springs.aspx?type=clutches_other&clutch_make=Honda&clutch_cc=650