John S.Wiker;59;of Belle Vernon;died Monday;Sept.11;1989;at his home.  He was born Feb.10;1930 in Monessen;a son of the late John S.and Marie Pottertie Wiker.  Prior to retirement;Mr.Wiker was employed by People Natural Gas Company of Monongahela.  He was a veteran of the Korean War;having served in the U.S.Army.  Mr.Wiker was a member of the Holy Resurrection Orthodox Church of Belle Vernon;where he was a former council member and president;the Monessen Elks and the Rostraver Township Lions Club;of which he was a former president.  In addition to his parents;he was preceded in death by a brother;William Wiker.  He is survived by his wife;Margaret Panko Wiker;two sons;John S.Wiker III and Leo W.Wiker;both at home;a daughter;Mary Margaret Wiker;at home;two brothers;Robert Wiker of Monessen and Joseph Wiker of State College;and four sisters;Mrs.Fred (Mary) Usher of Monessen;Mrs.Thomas (Helen) Bianchi of Allenpark;Mich.;Mrs.James (Kathryn) Caputo of Medford;N.J.;and Mrs.David (June) Abernethy of Carmel;Ind.  Friends will be received at the James C.Stump Funeral Home Inc.;Sweeney Plan;Rostraver Township;Tuesday from 7 to 9 p.m.and Wednesday from 2 to 4 and 7 to 9 p.m.  Family and friends will gather Thursday at 9 a.m.in the Holy Resurrection Orthodox Church;Belle Vernon;where funeral services will be held at 9:30 a.m.;with Rev.John J.Kluchko;officiating.  Interment will be in Belle Vernon Cemetery.  A Parastas service will be held in the funeral home on Wednesday at 8 p.m.  The James C.Stump Funeral Home Inc.is in charge of arrangements.