Clutch
Clutch slip can be eased by inserting extra steel plate, Friction plates can become hard and require replacement on some bikes well before wear limits are reached. Clutch baskets are prone to retaining rivets on primary gear working lose. Surface grinding the steel plates has been very successful. The larger heavier clutch fitted to 600 models can be used in earlier machines. Straight cut primaries can also be fitted to speed up clutch rotation and raise overall gearing. Clutch shafts can break if clutch securing nut loosens. These nuts have proved to be very difficult to undo on some engines. Some have had to be drilled to remove.
Weak point on Pantahs especially when tuned. Improvements made by using sintered bronze clutch plates and extra heavy springs. Clutch can be machined to accept an extra pair of plates. Early “small” hydraulic clutch on 600SL has a slipping problem which can be cured with new stock fiber plates and by substituting springs from a Suzuki GS1150. They are also found on some GS1100 models, and so appear to be readily available. They fit with just a bit of filing. The engagement is a little more abrupt but still very acceptable, and the slip has been non-existent for about 10K miles.