My 1992 KDX200 does this too, sometimes it just feels like there is no resistance, like the teeth have stripped off the starter dog, but I know this is not the case. I do not know what the gearing is in the kickstart but I assumed that this problem is when you start the kick just past TDC and therefore there is no compression at the start of the kick and the gearing means that you reach the bottom of the kick stroke before you have achieved much compression. I tried setting the piston to just before TDC by feel, as you would with a 4 stroke, before kicking and the problem went away.
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