The clutch system on the 00-03 GS is a weak point for at least some owners. The clutch can be prone to slippage.
The 04-05 GS/M Dual Spark F models have a revised clutch plate system, the G650 models have more changes.
The difference between the models is in the number of clutch plates. All other parts are common between the F models. Part No's for the G series are different, the changes are shown below and in the pdf.
The GS/M and G Series have a lower number of thicker clutch plates and increased tension. Details are below:
F650GS 00-03 - Inner Plates 8 x 1.50 mm and Friction Plates 8 x 3.50 mm - Total height 40.00 mm
F650GS 04-05 - Inner Plates 7 x 2.13 mm and Friction Plates 7 x 3.50 mm - Total height 39.38 mm
The wear limit for the early GS is 1mm reduction in total plate height (39 mm) so tolerances are tight.
It is thought the 04-05 model clutch plates could be used in the 00-03 GS but it is untested.
BMW tightened the oil specifications in the owners manual over the model years, gradually removing references to some SAE specifications and adding the JASO MA then MA2 specifications, see the About/AboutGS-Oils page.
The G650GS/X and TR650 clutch basket has a 36 tooth spline instead of 30 tooth spline so the clutch plates are different. The 7th steel plate has been replaced with a "Judder spring/support disk" as well.
The G Series also has an updated clutch release head and washer set to overcome the sticky clutch problem, the last of the F650GS models produced were fitted with the updated mechanism. It was also retrofitted if F650GS owners complained under warranty. It is not known if the parts fit the single spark model. Sticky Clutch Fix pdf
The 2010+ GS model clutch cable is different. The 00-09 Part No is 32737661757, 2010+ Part No is 32737728597
A pdf of what is known about the cable differences including the G650X and Husky Terra Download pdf
There are at least some G650GS which dont have a steel bushing in the clutch cover which causes problems in clutch release and first gear selection. 2007-08 G650X are also affected. See the pdf for details. The links page has a link to the original G650X write up on the problem. G650GS Clutch Release PDF
A combination of poor tolerances can result in poor clutch disengagement
The symptoms are:
The bike creeps when first gear is engaged with the clutch lever pulled in
Neutral is hard to find when the motorcycle is stationary.
The seal on the lever can leak - The seal dimensions are 12x18x4.5 mm
The correct procedure is to remove the clutch cover and push the seal out from the inside. Some owners have had success in removing the lever and the seal without cover removal.
When the clutch actuator arm is not positioned correctly the clutch cannot be adjusted. On the left is a 2012 model with the arm one notch too far anti clockwise. On the right the arm is correctly positioned.
Clutch plate replacement on the 00-05 F models is complicated by the combined clutch/water pump cover which requires draining the coolant as well as the engine oil. The rigid oil line is another complication. Refer to the BMW manuals for details on plate replacement. The Water Cooling Repair page has information on flexible oil lines.
EBC supply clutch plate sets for the 650GS
The EBC final plate does not fit offset as per the BMW final plate.
F650.com has some discussion on the subject.
The last EBC disk can be fitted without using the offset tab.
Or the tab on the last EBC plate can be ground to 13mm to fit the offset.
An alternative to the standard clutch is the Rekluse. Rekluse no longer list a kit for the 00-05 models but have a listing for the 08-15 G Series and Husky TR650. A drawback can be a lack of engine braking.
The pdf is the manual for the original 00-03 kit Download pdf