My G3L has always run rich (sooty spark plug invariably); the carb is a 276 and its got a 150 jet - which is what is specified, but for the Amal 275. As it happens, I have a spare 275 and am refurbing that to replace the 276, but have any of you gents set up the 276......if so, what jet size for a G3L? Cheers, Ferg