Technical Support for Navion System

Osborne Kit P/N AL-1 (TT2-1) Navion models A, B, D, E, F, and (twin) D16, D16A 

  Osborne Flush Aileron Balance Weight kit.  This replaces the factory external weights.

Description	Probable Cause	Correction
Weight screw will not start	Aileron pre-drilled skin hole not lining up	Tap out with 10-32 taping bit
Flush filler does not  harden	Not mixed properly or needed more hardener added	Remove filler and re-apply
Osborne Kit P/N 11982 (TT2-1) Navion models A, B, D, E, F, and (twin) D16, D16A Brief Description: Osborne Tip Tank kit consist of fuel lines routed from the Tip Tanks to a “cross feed” valve, then forward to the Osborne valve selector valve.  This valve is four position Left hand Tip Tank, Right hand Tip Tank, main tank and off.
Description	Probable Cause	Correction
Valve is hard to turn	Worn out/dry	Grease seat and replace shaft seal
Fuel stain at selector shaft	Worn out/dry	Grease seat and replace shaft seal
Handle is loose after installation of new clevis pin	Worn out handle and or selector valve shaft	Replace handle/valve assembly
Fuel bypassing valve	Worn out, foreign Debris caught in seat	Replace Valve
Valve handle is attached to selector shaft with a assembly screw on type (handle)	Non approved valve	Replace with approved part
Valve turns with no feel or tank position detenting	Wrong selector valve body or worn out detent assembly	Replace with approved part assembly
Osborne Cross Feed Valve P/N 55028   Kit applications: Navion Kit P/N 11982 (TT2-1)   This valve is used in level fight when Tip Tank is selected to achieve “cross feed” of both (LH and RH) Tip Tanks usage.
Description	Probable Cause	Correction
One Tip Tank feeds faster	1. Weak cross feed valve   2.Plugged Tip Tank vent  line	Replace valve Clear slow feeding Tip Tank vent line
No cross feed occurring when cross feed switch is selected “open”	1. No power to valve  2. Valve is not engaging	Check power source to valve   Bad coil replace valve
Tip Tank fuel is bypassing (siphoning) to opposite Tip Tank; in static condition. “Not in flight”	Seal in valve is worn out	Replace valve
Osborne fuel gauge P/N 55027    Fuel gauge (single) with selector switch.
Description	Probable Cause	Correction
Reads empty at all times with fuel in Tip Tanks	1. Fuel transmitter between Tip Tank and selector switch/gauge is grounded 2. Faulty fuel transmitters 3. No power to gauge	Check fuel transmitter wire for continuity, check power source
Reads full at all times with less than full Tip Tanks	Open fuel transmitter circuit.	Check fuel transmitter wire for continuity. Check for loose wire connection
Fuel Transmitter: See P/N 55025