[Darren69]

You can put Pro FST in which will help, it costs and it doesn't work that well but it can help things. Well I think you nailed it with KTM and Guzzi, they were both crappy injection bikes iiirc some of the Jap stuff from that era was rubbish too.

BMW and Ducati seem to have things sorted with IE back since the early '80's and Ducati won World Championships with their IE bikes don;t forget so they seem to know what works.

IMHO It's those long exposed inlet tubes that are the main problem, if you can insulate them from the cold air, you might stand a chance. Heating the carb bowls with warm oil does next to nothing as it only warms the fuel a bit which will only delay the icing a bit. They fitted electric heaters again to the carb bowls which does nothing more than the oil heaters did or didn't do.