4.Aircleaner / Luftfilter
| Picture | Order-Nr. | Description | Bezeichnung | Euro |
| 1401-38C | aircleaner J-slot , with logo | Luftfilter,einhakbar Chrom, mit Logo | 219,00 | |
| WL4-6 | transfer, round HOUDE oilbath | Aufkleber Ölbadfilter, rund | 8,00 | |
| 1402-41 | backingplate, aircleaner, civil | Rückplatte, Zivil-Luftfilter | 38,00 | |
| 1404-41 | metal mesh element civil | Filtereinsatz, Zivil | 32,00 | |
| 1405-41 | spring, filter | Federblech | 6,00 | |
| WL4-5 | brass instruction tag, nickle, 1941-up | Messingplatte , Nickel, ab 1941 | 12,00 | |
| WL4-4 | brass instruction tag, 1935-40 aircleaner | Messingplatte f. Luftfiter rund, 1935-40 | 12,50 | |
| 1406-36 | airintakehorn, flatheads | Luftfilter 36-38, Flathead | 110,00 | |
| 1406-41MA | connection carburator, aluminium | Anschluß, Vergaser, Alu | 37,00 | |
| 1408-36 | mountingkit, aircleaner | Montagekit, Zivilluftfilter | 22,00 | |
| 1408-41 | bolt, aircleaner mount, military | Montageschraube,Militärluftfilter | 2,75 | |
| 1409-41M | screw, connection carb. | Schraube f.1406-41M | 2,00 | |
| 1411-41M | hose, connection | Ansaugschlauch | 12,00 | |
| 1413-41M | clamp, hose | Schelle, Ansaugschlauch | 9,50 | |
| 1416-42 | screw, plate, NOS | Schraube f. Platte, Original | 3,30 | |
| 1421-42 | oil cup latch | Verschluß-Bügel | 3,00 | |
| 1423-42 | spring clip, oil cup latch | Haltefeder f Bügel | 2,00 | |
| 1426-42 | gasket, aircleaner | Dichtung | 4,00 | |
| 1430-41M | plate, mounting | Halteplatte, Ölbadluftfilter | 29,50 | |
| 1430-40M | plate, mounting, round type | Halteplatte, Ölbadluftfilter, rund | 32,00 | |
| 1432-41 | clamps, plate to frame, pair | Rahmenschellen-set (2) | 7,00 | |
| 1425-41 | aircleaner guard WLC, cmpt. | Schutzbügel, Luftfilter WLC, kpl. | 99,00 | |
| 7223-34X | bolt, frame clamp + nut | Schraube + Mutter f. Schelle | 4,00 |