thanks for the replys
it does fire a bit when i give it a few revs but still does not seem as good as the front cylinder,i have done a top end compression test and got 90psi on the offending cylinder and 105 on the front cylinder.piston and rings only 900 km old so i am suprised compression is this low.going to remove cylinder and fill the crank with petrol to see if it leaks as i dont have the gear to do a proper leak test.i haved swapped the coils and put new plugs in but that is all i have done electricaly