bw photo into cmyk file

[kentucky]

I have a 2 color print job. I want my photo (part of the file) to be grayscale. the background is 100% black with monochromatic noise. A few parts of the design have 100% magenta. 2 color design-100% black, 100% magenta.
Why is my photo changing to cmyk when I brought it in as b/w. Do I have do redo my entire design ? It is the only thing that has coverted to cmyk.
Any suggestions?

 

[kentucky]

I think I figured it out. I selected the b/w photo layer. Clicked on channel mixer, clicked on monochromatic, then adj. the contrast with autocontrast. hopefully that will separate correctly.

 

[jmgalvin]

If you have any color, the image cannot be grayscale. Have you tried duotone?

Using OSX 10.3.8 on a G4

 

[kentucky]

after using channel mixer (checking monochromatic), my original b/w's are now gray , the only other color I had was 100% cyan. so that gives me a 2 color design. yes, it separates from quark. i was worried, hopefully it will print ok.