Warner Motor Service Letters

These Warner Motor Service Letters are courtesy of Schaeffer Sondey, owner of Monocoupe 90 A, NC18192.

A-1            Exhaust Valve Retainer Washer P/N
A-2            Ball Bearing Crankshaft Thrust P/N B-550
A-3            Excessive Cylinder Wear
A-4            Valve Springs
A-5            Relocation of all Propellers in the Hubs
A-6            Valve Spring P/N 7741
A-7            Service Memorandum to Owners of Airplanes Powered by Warner Super-Scarab 145 HP Engines
A-8            Valve Springs
A-9            Replacement of Link Rod Bolts
A-10          Replacement of Exhaust Valve Springs
A-11          Periodic Inspection of Crankshafts on 125 HP Engines
A-12          Valve-Carburetor Heat Control Assembly No. 8290 – Modification of Linkage
A-13          Pistons, Exhaust Valve, Cylinder, Link Rod
A-14          Spark Plugs-Installation, Inspection, Maintenance, and  Overhaul
A-15          Cylinder Attaching Studs – Proper Maintenance,  Inspection, and Assembly Procedure
A-16          Carburetor Heat Control Valve Assembly No. 7720 and 7719  Drilling of Drain Hole to Eliminate Fire Hazards
A-17          Replacement of Cylinder Hold-Down Stud, Gasket  between Cylinder Barrel and Crankcase
A-18           Recognition of Reinforced Taper Crankshaft and  Availability of New Heavier Stem Exhaust Valve
M-10          Valve Springs for New Engines
AD 51-04-02 Cylinder Hold down Studs