Rough engine problems 1.6 ez

Hi guys
Hope someone can help
I've got a mk1 golf cab 1.6 carb, engine ez( I think )
I took the plastic cover off my cam belt yesterday, the bottom cover, because it was loose and rubbing on my water pump pulley. I did not take off the cam belt or crank shaft pulley to take the cover off so I couldn't of altered the timing, however I did turn the crank shaft pulley by hand.




Anyway today I went I start the car and the car sounded very rough and wouldn't rev beyond 3 and a half thousand.




I've taken the carb off and emptied just incase is
Was flooded.
I've had a look at the spark plugs just incase they weren't firing, they all looked dry and had not dirt on them.
Can anyone help diagnose what might be the problem.

Also when I turn the car over, the engine makes what sounds like a bang noise as it starts and then it sounds like it's not firing on all 4.



Cheers in advance

check the timing anyway, the belt may have slipped when you cranked it over by hand