Injini iyenera kuyamwa mpweya wambiri panthawi yogwira ntchito. Ngati mpweya sunasefedwe, fumbi loyimitsidwa mumlengalenga lidzayamwa mu silinda, zomwe zidzafulumizitsa kuvala kwa gulu la pistoni ndi silinda. Tinthu tating'onoting'ono tomwe timalowa pakati pa pisitoni ndi silinda imatha kuyambitsa "kukoka silinda", komwe kumakhala koopsa kwambiri m'malo owuma komanso amchenga. Fyuluta ya mpweya imayikidwa kutsogolo kwa carburetor kapena chitoliro cholowetsa kuti zisefe fumbi ndi mchenga mumlengalenga, kuonetsetsa kuti mpweya wokwanira ndi woyera umalowa mu silinda.
Malinga ndi mfundo kusefera, zosefera mpweya akhoza kugawidwa mu mtundu fyuluta, centrifugal mtundu, mafuta kusamba mtundu ndi gulu gulu.
Pakukonza, gawo la fyuluta ya pepala siliyenera kutsukidwa mumafuta, apo ayi chinthu chosefera pamapepala chidzalephera, ndipo ndikosavuta kuyambitsa ngozi yothamanga. Pakukonza, njira yokhayo yogwedezeka, njira yochotsera burashi yofewa (kutsuka pa makwinya) kapena njira yoponderezedwa ya air blowback ingagwiritsidwe ntchito kuchotsa fumbi ndi litsiro zomwe zimayikidwa pamwamba pa pepala losefera. Kwa gawo lazosefera, fumbi lomwe likusonkhanitsira fumbi, masamba ndi chitoliro chamkuntho ziyenera kuchotsedwa munthawi yake. Ngakhale itha kusungidwa mosamala nthawi zonse, chinthu chosefera pamapepala sichingabwezeretse magwiridwe ake apachiyambi, ndipo kukana kwake kutulutsa mpweya kumawonjezeka. Chifukwa chake, nthawi zambiri, chinthu chosefera pamapepala chikafunika kusamalidwa kachinayi, chiyenera kusinthidwa ndi chosefera chatsopano. Ngati chinthu chosefera pamapepala chang'ambika, chobowoka, kapena pepala losefera ndi kapu yomaliza zachotsedwa, ziyenera kusinthidwa nthawi yomweyo.