Ama-spark plug, aziwa kakhulu ngokuthi ama-fire plug, azosebenza njengokuqhuma kokukhishwa kwe-piezoelectric enamandla aphezulu kusuka ku-lead enamandla aphezulu (i-fire plug), ezophula umoya phakathi kwama-electrode ama-spark plug, ikhiqize ama-spark kagesi ukuze kuvuthe ingxube yegesi ku-cylinder. Izimo eziyisisekelo zenjini esebenza kahle kakhulu: i-spark eqinile yamandla aphezulu, ingxube efanayo, isilinganiso sokucindezela okuphezulu. Izimoto ezinezinjini zokushisa zangaphakathi ngokuvamile zisebenzisa uphethiloli nophethiloli. Emakethe yezimoto yaseShayina, izimoto zikaphethiloli zithatha ingxenye enkulu. Izinjini zikaphethiloli zihlukile kwezinjini zikaphethiloli ngoba uphethiloli unendawo yokushisa ephezulu (cishe ama-degree angu-400), okudinga ukuvuthelwa okuphoqelelwe ukuze kuvuthe ingxube. Ngokuphuma phakathi kwama-electrode ukuze kukhiqizwe ama-spark, injini kaphethiloli idlula engxubeni kaphethiloli negesi ukuze ikhiqize amandla, kodwa njengoba uphethiloli kaphethiloli ngisho nasendaweni eshisa kakhulu kunzima ukuwuvuthela ngokungazelelwe, ukuze kuvuthelwe ngesikhathi kuyadingeka ukusebenzisa "umlilo" ukuze kuvuthe. Lapha ukuvuthela i-spark kuwumsebenzi "we-spark plug".
