Cannot print with tiled output ?

Hi everyone - this is my first post here, and I hope someone can tell me what I'm doing wrong.

I just got a new printer, and I'm trying to use it for my first printing job. I am attempting to print out a pickguard outline for a bass guitar. The outline needs to be full scale (printed out 100% size, tiled on two 8-1/2" x 11" sheets of paper). The printer software doesn't have the option of printing large documents, so I downloaded and installed Adobe Reader, in the hope that I could print posters and banners which are larger than one sheet in size.

The printer I'm using is an HP Office Jet Pro 6830. What is happening is that when I open Reader, and attempt to use it to print this job, the software is not giving me the option to print with tiled output. When I set my preferences and hit print (while in Reader), the print window that was there before I installed reader comes up (the same HP print window that appears when you are not using Reader). It appears to be overriding Reader. I end up printing a pickguard outline scaled down to approx.  60%. The pickguard outline is printed on one 8-1/2" x 11" sheet.

I have a two screen shots showing what is happening when I hit the Reader print icon, but I can't attach them here ? I don't see the paperclip anywhere. Anyway, If someone could suggest how I could beat this problem, that would be great.