For what I read for now there is no manual for the X-12 except a poor copy of I dont know what.
Here some setting I took in another post
Originally posted by Grinder Hi. The X12 is not the same engine as the NSR12. The NSR is microcast piston, and the X12 is not. Also the timing is different. The X12 is better. The base needle settings for the Mugen X12 are 5.5 turns out on the high speed needle, and 3.5 turns out on the low speed needle. Needle settings will vary dramatically depending on the type of fuel you run, weather, and if the engine has any internal modifications. I have found that on the X12 the low end, and spraybar are pretty close from the factory. The high speed needle is set for break in from the factory.