Try ebay!
They have, for many or most outboards:
1. Original but used factory service manuals.
2. The Seloc and/or other after market manuals, new and/or used.
3. CD-ROM copies of the original factory service manuals for as little as $5-$10 each. (These may be "bootlegged" or illegally copied editions, but they've got the whole show right there for cheap. I'd buy the factory manual from the dealer if I had to, but the typical $75 is just a bit much of a gouge, IMHO.)
4. Here's the online Factory Service Manual for the 2005 Yamaha 90 EFI outboard for anyone who wants to use it that I ran across on a web site once.
2005 Yamaha FD-90 Service Manual
I suggest those of you who can use it download it and keep it, just in case they decide to deny us access to it. Sneaks and I tried to deduce the codes for all their manuals from the one listed, but without success.
The 75 and 90 differ very little except on fuel injection and perhaps ignition computer programming and a few minor hardware issues. I doubt the manuals for 2006-2009 are much different.
Happy Hunting!
Joe.