The forward compartment contains the radio battery and the fuel pump battery (retained with (2) rubber bands), the E.C.U. and radio switch are mounted to the plywood platform. A group of 3, labeled air fill valves (arrow) are stored up front. They service the 3 independent air systems, retracts, speed brakes and the wheel brake system. The fuel line from the main tank to the pump is interrupted with a festo on/off valve. We disconnect here for fueling.

With the cockpit tub removed you can access the rudder gyro and the receiver (arrow). The retract air selector valve and servo are adjacent to the gyro. Forward end of the main fuel tank is visible.

Bypass cap is removed to show the engine installation. #1 is the engine temperature probe inserted into the tailpipe and held in place by engine mounting straps. #2 are the glow plug wires. #3 is the fuel “in” line, it T’s off inside F/G cowl to connect also to lubrication system. #4 is Teflon tubes exiting the F/G cowl for the propane, air start and pressure sensing lines. #5 is the Saito fuel filter installed between the fuel pump and engine. Arrow on filter points towards the pump. #6 air connectors are required if main gear inner doors have the cylinders mounted in wings.

Bypass top is retained by Velcro straps glued to the bottom of bypass duct. Notches in front of top are for various tubes and electrical wires to exit forward. Kevlar safety band snaps into place over wooden wedges. Notice that the F/G bridge has been cut away to allow engine installation.

Smooth Stop valve and servo is Velcro mounted to fuse side. All 3 air storage tanks can be mounted beside and below tailpipe. Aluminum tailpipe cooling shroud has a 1/8” plywood ring that mounts to F-4B with (2) #2 SMS (arrow). Stainless steel tailpipe is retained to the CF bypass duct with (2) #4-40 bolts and nuts (glued to inside). 1//16” wires that retain the fwd hatch are shown in their full aft position.

Speed brake cylinder is protected from tailpipe heat with a piece of ceramic blanket on each side. Apply a drop of Zap-A-Gap to airline on plastic nipple. Use only 40-45 p.s.i. in speed brake system.