Luke,
You can get the engine interface adaptor cable and the extension cable through trymax marine in brisbane, they have them in stock or you can get them from browns point marine.
given the Australian dollar at the moment it would be worthwhile checking both prices.
Fatnhappy,
sorry didnt see you question earlier, but the interface adaptor is as follows;
http://store.brownspoint.com/detail....id=990C0-88035
and the plug on the end is incorrect. Browns point advise you to use this connector as a replacement to your analogue gauges, this is incorrect, it should be connected in the engine bay, to do this you will need a yamaha wiring harness. I have done it and have it working successfully.
Regards
Honda