kmx 125 won't start

[nickfixed]

Last summer i me and my friend had a huge amount of fun this bike. however, over the winter months, it fell into the hands of his big brother who promptly ripped the wiring out for reasons unknown. i've replaced the wiring loom, replaced the plug, rebuilt the carb, cleaned the air filter, and flushed it with clean petrol and oil.
Everything seems to be as it should, except the spark. when it does spark, it sparks very strongly, thought it only sparks about 2-4 times out of every ten or so kicks.
I'm really stuck as to what the problem is, so any help would be hugely appreciated

Oh, and my friend decided at some point that it'd be a good idea to try and make a working loom out of the few remaining wires.

nick
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First bike project/always learning