Fuel Feed Arrangement 900 Trident

Both feed pipes from the carbs fit to separate outlets on the fuel tap and a 3rd smaller tapping is for the vac pipe off the rhs ( no. 3 ) carb as you suggest.

The 2 breather pipes go up and over the top of the air filter and then down following the spine of the frame.

Don't attribute this to @Rocker as I was first

 

Just a thought ..........

Make sure you have the preformed pipes for the carb feeds as there is a good possibility that they will kink otherwise causing issues with fuelling.

As you are rebuilding it all I have found it usefull to reposition the main wiring loom where it follows the spine of the frame down towards the airbox from the ignition coils from the LHS of the frame behind the fuel tap location to the RHS as this gives more room for the fuel pipes to be fitted without kinking or being pinched.

 

Theres still a bit of movement in the loom at that point, just above the airbox, once you have the tank fitted you will see its very tight otherwise. I would still pull the loom to make as much space as you can.