Susan wrote on 12/31/69 at 16:00:08:I asked the same question recently and was reassured that the latest Clymers (which lists through 2003) will work just fine for the 2004 bikes. The changes made between 2003 and 2004 were very minor and not mechanical. Here is the list of what was new for 2004:
FEATURE LIST: Suzuki 2004 SavageŽ 650 (LS650P) New- New rear view mirrors for more attractive appearance - similar to VL800 Volusia
- Standard 4-way emergency flasher and and high-beam passing switch
- Multi-reflector turn signals for improved appearance
That said, even though one of the differences was the style of the turn signal I think that the way to get it on and off is no different so the manual should work just fine.
The only thing that would be impacted by the new "improved appearance" is one's subjective thinking

Aside from that there will only be minor changes in the electrical schematics for the addition of the 4 way flashers.
Does the '04 model also have the "headlight off" feature during startup? that would be another change, if so.