Not sure if this is of any use to anyone but here goes .....
So this is my final setup for the dual tanks on my S28...
So lets start with the pipe set up:-
From Tank 1(Original) we take the RED tube from the tank Output to the Return of Tank 2 (New Tank)
From Tank 2 Output we take the BLUE tube to the fuel Primer Bubble(see note 1 below)
From the Primer Bubble its the BLUE tube to the Fuel Filter(see note 2 below)
From the Fuel Filter its the BLUE tube to the Carb
Lastly we take the GREEN tube from the Exhaust to the return on Tank 1...
Note 1:-
A few folks have said they take out the Primer Bubble.. ive left mine in . to get rid of any trapped air when priming just remove tube from the carb and put it into your filler bottle .. pump the bubble a few times to get rid of the air, then just put the tube back on the carb,... oh and chuck the fuel back in the tank..
Note 2:-
Fuel Filter was just a few quid from ebay, i drilled 2 small holes into the black plastic gaurd thingy and just cable tied it in place..
Hope this makes sense to folks .. any questions .. just ask ..