Motorcycle Repair: Clutch, engine oil viscosity, clutch plate

Question
I have a 1982 HOnda 750 Magnum. The clutch recently stopped working (will not disengage).  Checked the fluid seems to be fine,although low.  Filled up and still does not work.  Any ideas as to why this suddenly happened or how to repair?  

Answer
Hi Dave,

Clutch not disengaging properly, check the following:

Clutch lever play excessive
Clutch plate warped or too rough
Clutch spring compression uneven
Engine oil deteriorated
Engine oil viscosity too high
Engine oil level too high
Clutch housing frozen on drive shaft
Clutch release mechanism trouble
Clutch hub locknut loose

Respectfully,
Mark Shively