Motorcycle Repair: 1979 honda xl185s timming, camshaft lobes, punch mark

Question
were should the timming marks line up for igntion timming and cam timming?

Answer
Arthur,

The camshaft lobes should be rotated so they are DOWNWARDS in an inverted vee  /0\ so both valves are closed on the top of the compression stroke.

The piston is located at the top of the stroke (T mark on the rotor/flywheel). Cam sprockets generally have a o punch mark on them which is at 12 o'clock position when bolted to the camshaft, camchain connected and piston still at TDC. Depending on the orientation of the camshaft flages to the lobes, the bolts will either be at 9 and 3 o'clock or 12 and 6 when cam timing is correct.

Ignition timing is set so that the lines on the pulse generator line up when the piston is at the F (firing) mark.

Bill Silver