* Bad weather prevents experts from flying to the platform * Total says flight pushed back to Thursday, Friday * Experts to assess options to stop the gas leak By Oleg Vukmanovic and Henning Gloystein ABERDEEN/LONDON, April 4 (Reuters) - French oil major Total has further delayed plans to fly engineers to stem an 11-day leak of explosive gas at its North Sea Elgin platform due to continuing adverse weather conditions, a company spokesman said on Wednesday.