Mphete ya Piston ndi mphete yachitsulo yomwe imayikidwa poyambira pisitoni. Pali mitundu iwiri ya mphete za pistoni: mphete yoponderezedwa ndi mphete yamafuta. Mphete yopondereza itha kugwiritsidwa ntchito kusindikiza mpweya wosakanikirana woyaka muchipinda choyaka. Mphete yamafuta imagwiritsidwa ntchito pochotsa mafuta ochulukirapo mu silinda.
Mphete ya pisitoni ndi mtundu wa mphete zotanuka zachitsulo zomwe zimakhala ndi mawonekedwe okulirapo akunja. Imasonkhanitsidwa munjira ya annular yomwe ikugwirizana ndi mbiriyo. Mphete za pistoni zobwerezabwereza komanso zozungulira zimadalira kusiyana kwapakati pakati pa mpweya kapena madzi kuti apange chisindikizo pakati pa bwalo lakunja la mphete ndi silinda ndi mbali imodzi ya mphete ndi poyambira.
Mphete ya pistoni ndiye gawo lalikulu la injini yamafuta. Imasindikiza gasi wamafuta pamodzi ndi silinda, pistoni ndi khoma la silinda. Ambiri ntchito injini zamagalimoto ndi mitundu iwiri ya injini dizilo ndi petulo, chifukwa cha ntchito mafuta ndi osiyana, ntchito mphete pisitoni si ofanana, mphete oyambirira pisitoni ndi kuponyera, koma ndi kupita patsogolo kwa luso, chitsulo mkulu mphamvu pisitoni mphete anabadwa, ndipo ndi mosalekeza kusintha kwa injini ntchito, zofunika zachilengedwe, zosiyanasiyana zapamwamba pamwamba ntchito ntchito mankhwala, monga plating, plating, plating nitrogeni thupi, zokutira pamwamba, nthaka manganese phosphating mankhwala, kuti ntchito ya mphete pisitoni bwino kwambiri.
