Motorcycle Repair: CM 250 Cylinder Head Torque Values, cylinder head bolts, torque values

Question
I have removed the cylinder head from my nieces 1982 CM 250 to repair vandalism to her spark plug hole. What are the torque values for the cylinder head bolts (studs) and nuts.

Answer
I don't have a manual for that bike but the standard torques for the thread size would be close enough.  I'd use the 8.8 grade torques below (foot lbs.


Regards
Rich

Bolt size Low Grade Grade 8.8 Grade 10.9 Grade 12.9
6mm           3-5       7       10          12
8mm           8-12     17       24          29
10mm        15-22     33       47          57
12mm          39       59       83         100
14mm          60      101      131         158
16mm        60-94     146      202         247
18mm       60-130     201      283         340
20mm      166-188     285      401         482