Originally posted by cdelong
the X12 is basically a Nova Rossi NSR12 engine. My carb settings are 4 1/2 out on the top end, 3 1/2 out on the bottom end. Keep in mind, my friend has the same engine and his top end is 5 1/2 out on the top. Needles do differ, but this should get you in the park.
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.
