back in this same thread, Bikeguy Joe tells you how to test for spark.
"First, take the plug out, and turn the engine over with the plug in the plug wire, and grounded to the engine, you should have spark. If you have spark, then you may have a fuel problem.....Make sure you have fuel flow to the carb. If you have a spark and fuel, then you may have a fouled plug (it will spark when out of the engine, but not under compression) Also, just because the plug sparks, doesn't mean it's not fouled.
One more thing- these Chinese engines have notoriously bad spark plugs....do yourself a favor, and buy a good name brand replacement (NGK, Bosh, Autolite, Champion)
Also, to check your spark, you may need a helper.....someone to walk the bike or turn the back wheel while you hold the plug to the cylinder head. "
If you've replaced the sparkplug, then you should have spark. but you should check anyway.