The engines below have been fitted by the manufacturer with an exhaust valve 32 mm (1.26 in.)part no. 854113 with a variety of production lots from which the production lot numbers 0317 and0517 (see Fig. 2) are affected.All versions of ROTAX ® engine types 915 i A, 915 i B (Series) and 914 Series are affected, if atleast one of the described criteria applies: