anybody know the importance or information behind this factory casting on an ar it also has a mugen brain above the airbox

Above the airbox? Where exactly?

sorry knackered i just mean the ecu unit it is a very quick bike and i wonder what else may be mugen related 1997 bike 160kph easy on 14\42 sprockets i have another ar 2000 owned from nearly new 14 years also with a mugen ecu so im used to the model tom at leisure trail waw not much help if anyone knows you will!

Look through the FAQs to find answers. Start with the ECU section.

thanks will do

cant see anything mugen related on FAQ only other item ive heard of is a mugen aftermarket piston i wonder if its had a reed replacement as it seems to leap forward once the revs build my other ar has a much more linear power curve ?

Mugen made ECUs, cylinder heads, carb kits, premix kits, seats, exhausts and suspension mods for the AR. Further research will tell you what they do............

thanks it sounds like it might a carb kite it feels like its getting a boost from somewhere ! im just enjoying it

No it will be the ECU. Carb kit is for premix and/or cylinder head. Maybe nothing at all just a sticker. Different power delivery could be a whole heap of things. I don't know of any casting in the position you mention so assuming is a sticker but photo would help.

thanks for your advice knackeredMk1 i will keep delving into it its def a casting on the l,h.s. servo crankcase with japanese writing as well i will work out a way of getting a photo on have to ask my son as im a tecnophobe of 62years old

OK so it's not near the air box! What you describe sounds like the cover over the power valve. That cover comes in the package that has the Mugen cylinder head. So it is likely that you have that but people do sell them on their own.

knackeredMk1 wrote:OK so it's not near the air box! What you describe sounds like the cover over the power valve. That cover comes in the package that has the Mugen cylinder head. So it is likely that you have that but people do sell them on their own.

+1. is it about 3"x 2" square?
Mike