You don't say what engine the Weber carbs are fitted to? O
If you have fuel and a spark then it should start unless the ignition timing is out ?
Have you got the spark plug leads back on the correct plugs?
Arwyn
Arwyn - in the signature it says 1976 4/4 so assuming Xflow (I think if you access the forum from a mobile, you don't get to see the signatures).
Dave - as Arwyn says - as you've got a spark and fuel it could be a plug lead issue - anti clockwise rotation and firing order 1-2-4-3.
And if there was a bit of rubber in the float valves - could there possible be a tiny bit blocking the idle jets? I had this issue with mine, but it was a Weber 32/36 DGV.
