All of the above Charles has said is true, but the state of your piston will not account for it being hard to start. Dodgy battery, coils or plugs are more likely and there is a bit of a knack to kicking one up.

The technique is hard to describe you really need to have a good feel for where the piston is in the stroke as the kick only moves it about 1/2 a cycle and some bikes are just hard to get gong. Andy's has been for a long time for example but mine are both fine and go with your hand on the kickstart first push. Yet as a search will confirm I'm hardly Mr New.Parts (2nd hand bits, rings and clips included on both my race and road bikes, not recommended by any means but needs must and all that).
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Please do not PM me technical questions, if you can't find it on the Forum start a thread