Help please, after looking at the responses to earlier problems of toilet flushing i identified that i needed a new syphon which i duly bought and fitted (close coupled) however after a number of hours of frustration and attaching the handle levers and hook in various positions i am still unable to flush the toilet properly some times it takes two flushes others theree or four, i have checked the stop cock valve and all is ok. if i pull the syphon hook up directly by hand hard then it flushes first time. The water level in the toilet comes to the same level as previous when refilling. i do not have any leaks the unit is a 9.5 inch high syphon from B&Q. i have looked closely at the unit and can not see anytthing faulty with it.
Advise greatly appreciated.