first take out your spark plugs and hold them to cilinderheadnut and push the
start button (this hurts sometimes

), check if you see a strong bleu spark , a yellow or orange spark means you have a weak spark, I would check all connections if so
If you have a bleu spark, put the spark plugs back, take of your flamearrestor and than put a little bit off feul in top of the carb, and try to start the engine! take out your spark plugs if it won't start and see how the look,
when they are wet, clean them and try again!
Be carefull if it starts, don't let the engine run for longer then 20 seconds
when there is no garden hose connected to your engine, there are oilseal
that can't take the heat!
Good luck!