Small Engines (Lawn Mowers, etc.): I.C.ENGINES, camshaft, crankshaft

Question
What are the advanteges/ disadvanteges for an engine when power taken from  camshaft/crankshaft?  

Answer
I don't understand your question fully.  The power output is generally from the crankshaft because it is more robust and directly connected to reciprocating assembly.  The camshaft also spins at exactly 1/2 of the speed of the crankshaft.  Although accessories can be run off the camshaft, the torque and RPM requirements would have to be low.  Hope this helps.