You still need lilo eventhough you're not using windows.
What you need to do is remove xp menu and change lilo timeout in /etc/lilo.cfg.

ex:
remove :

other=/dev/hda1
label="WindowsXP"
table=/dev/hda

**make sure default is set to Linux if in previous it was set to XP.

Reduce the value of Timeout section if you want to boot to default faster.
**Dont forget to run : lilo -v after you edit your lilo.cfg.