Alternative K&N Air Filter for Rotax 825551 (does not have locking wire tab) FIG. 5 on 912 Instruments, Air Filter Diagram FIG. 2 & 7 on 447, 503 & 582 Air Filter Diagram Small air filter - to fit directly onto Bing carburetter Suitable for Rotax 2-stroke single or twin carb engines, dependant on jetting, please see parts lists. (2 required for twin carb engines)