REDEX .. No, not Red Necks, RedEx. Don't know if its available in Oz, but we used to use it all the time in U:K. Sounds similar to the Nulon stuff mentioned in that you'de pour it direct into the carbies, but it was also available at the servo pumps in a hand held pump that discharged a measured "shot". 1 Shot / gallon and the engines where always clean and smooth. Nowadays I use 'Industrial Chemical Tecnologies F-10 Fuel Treatment. 6ml / tank full. Seems to work as the tick-over is sweet and smooth, even down to 400 rpm on test.