As I said in the original post, I'll probably be able to get one eventually after CNY (everything is currently closed), though I have been told (by Taiwanese mechanics, who do tend to be full of it) that it won't fit. This "female" type of nipple seems to be required to fit the "male" end of the Gunson adapter, but I don't know whether the size and thread pitch (which may not be "universal") are necessarily going to be compatible, and, as noted in the initial post, I've been told that they aren't. As described in the original post, they don't ALWAYS, ALWAYS come with one here, because I bought one a few years ago and it didn't have one, just the bare thread. The usual car plugs here don't have that type of nipple, as shown in the linked picture.

With COLORTUNE fitted, in place of a sparking plug, the flame is visible through the glass insulator and the fuel is ignited by a spark in the COLORTUNE. Multi-cylinder engines, particularly those with twin or multiple fuel systems are best tested with a Colortune in each cylinder.A high speed fuel feed and adjustment (main jet and main mixture screw) normally located closer to the inlet air cleaner mounting flange.The main fuel discharge feeds into a venturi shape, whose restriction (a fixed size choke) gives a low pressure to pull the fuel in. This allows the user to obtain greatest engine efficiency by assessing the colour and appearance of the flame and correcting any faults thus revealed. The complete Colortune kit is also available in the following options: G4171 (with 12mm Colortune Plug) and G4172 (with 10mm Colortune Plug). These products has a smaller internal volume which maintains the normal compression ratio and a higher heat range, more suited to high perform. ance engines.

If there is perfect combustion, all the fuel will be burnt to produce carbon dioxide and water with no carbon monoxide or unburnt fuel (hydrocarbons).

Real MPG

Determination of the quantity of air going into the engine is itself a difficult task under conditions of varying temperature, varying pressure, and with extreme disruption to the flow caused by valves opening and closing at an incredible rate.