Not a silly question, I’m the one who asks silly questions. When I got it you could see a puff of blue smoke where the LH transfer port didn’t bed completely. That is ok now after carefully trimming the gasket to fit and the spitting is certainly improved. Richard Tann advanced the ignition as well before handing it over and that helped a lot. He has also tried a baffle in the past without success. Luckily I can live with the spitting and work round it by avoiding small throttle openings (!). I’ll have a go at making some gauzes, hours of innocent fun in prospect.