Right i've just taken some pictures before dark, still can't see much but i've got a somewhat idea of how it works just not what it is, please correct me if i'm wrong though as i love to learn.
1

where i've circled i THINK this is the main fuel feed correct me if i'm wrong though..
2

then it passes through the ufo (unidentified fucking object) judging from where the arrow for flow is pointing then..
3

this is where it loops back into the perc housing bit you can see the change is hose type if you get me then..
4

then it goes into the carb. you can see the the item in question bottom right of this photo, hope this helps i'll post more pics tomorrow when i get the perc fan off, cheers for the help guys