Fuel Tap Fit & Management #14,17

For connecting the overhead auxiliary fuel tank to the main supply there is a neat fuel management solution. I needed a nice but small tap, to permit draining down -when required in flight - and getting the balance from the top tank completely into fus. tank.

One simple answer did the whole job.
An  "On/Off" 90 degree 1/4" lever tap petrol (gas) tap, inserted in the top tank outlet down pipe was secured to the door frame, placed within pilot's reach . The tap has ON/OFF markings added near its logically pointing lever.
The top feed is tee'd into the bottom main feed pipe leading to the plane's main ON'OFF in line tap.

Turn the lever tap OFF and fill overhead and fuselage tanks individually as required. Remain within the maximum allowed a/c gross weight.

For Take off and initial flight, leave it OFF & run from the fuselage tank. When it's down to ~5 litres, turn on top tank. [If you've got the larger capacity top tank drop it down in two separate stages]
And that's it !  Before refuelling just close he top tank tap again.

N.B.
Wt. & Balance programme was used in calculating for my own bare a/c weight figure with added P1 'crew' & tools/Radio load, plus allowing for refitting the top tank etc.
Notably the C of G moves forward right up to the max permitted position of 58.5" as main tank fuel is used. But even fully loaded, the aft C of G @ 60" is at worst whole inch forwards of permitted rear position. i.e. 40 % of the meagre 2 .5" range of 58.5 to 61 inches from reference datum.
Pictures
The top tank line via the new 90 degree Tap (heading photo.) joins the main tank feed at the gascolator (behind the right lower side rear of the seat).
This feeds through one pipe forwards via the primer bulb to the main ON/OFF fuel tap.
Then forwards to the firewall & engine, passing the in-line see through filter on the way.