Hi pau13z, welcome here and you have one of the best mowers ever built. The first thing I do once I have done all the tests you have done is fit a proper float needle, not those rubbish plastic ones on ebay, they just don't work. You need one of the brass/viton tip ones. I get 80/90% of mine running this way but there is always the odd one with compression that just won't fire up. These are the ones that even with a squirt of starter fluid down the plug hole and I can't get a peep out of them. These will not start, even after fitting one of my modified carbys on it. These I just put in my pile of non running Powertorques I might get back to them one day. Try the needle and if that doesn't work try the carby mod here, bit of work but guarantees to get them working. I do a number of these every week.
