This is a common problem last time this happen we pulled the carb out and cleaned it then it got up and going.

Then when we stopped it the damn thing wouldnt start again. Check the spark plug and the spark was gone.
new 5 pin CDI has only the kill switch on the handle bars to it. I have cut off all lights and traced wires re wired and beautiful a white spark something must of came loose.
Still does not start , new carb ordered installed checked the clearance on the tappers they were tight have set top and bottom to .05mm slight movement now.
The spark plug is dry no sign of fuel going down, i place my hand over the air filter side and i get fuel over my palm.

i have tried start ya bastard in the chamber nothing when squirted some fuel down into the chamber.

i have also replaced old fuel, any further ideas would help i have gone through all the posts and tried every thing.

 

Check the compression. Check the valves were set at TDC on the compression stroke. Check the T mark on the flywheel is at TDC of the piston. Check the valve timing mark agrees with both.

 

When i checked today and adjusted valves to .05 the T was central on compression stroke the tc was center of the head bolts.

 

I have VERY similar issue. In the past I have given my ATV a good thrashing and owned it since new. However I have been replacing the oil in it very often, way more often than required. Then one day my ATV stopped running. I then, like you ,cleaned the carb as a load of dirt was in there. This helped my ATV to fire up straight away. After that it would cut out and would need cleaning much more often (approx 10 mins!). After having enough I replaced the carb and the ATV fired up right away. Mechanically I have had no issues since, just MANY electrical issues that I am trying to solve.

All I can recommend (not knowing a great deal about these bikes) is to replace the carb as is cheap as chips for these bikes and make sure the air : fuel ratio is correct.

Does the bike crank over at all?

 

Also forgot to ask, Have you replaced the spark plug? As I found that mine wasn't producing spark, and when replaced with genuine NGK spark plug (just for servicing) it produced spark.

Hope this may help!