Hi,
I followed the carb overhaul guide but my right hand 2 x cylinders dtill do not function. After a lot of searching and faffing about i poured a little fuel into the top of the carbs whilst running and this seemed to resolve the issue.

Given the above i can only presume that the cylinders are not getting any fuel.

What could the causes be please? The float bowls seem to be filling with fuel?

Take the float bowl covers off and have a look at the general cleanliness in there. If its full of golden like tar, the carbs need cleaning due to blocked jets.

No it all looks pretty clean and the float level switch filters are nice and clean too.