I did change glow plugs, from the original to an OS #8 with no change in behaviour. My main needle is about 2 1/4 turns out. It behaves normally when adjusting the top end. I might just try a fresh jug of fuel as I had mixed some 5% and 10% leftovers from last year at about 50-50. My MVVS 49 doesn't complain about this however...