It is pretty easy to create a bootable USB Mavericks Installer. You just need an 8 GB USB stick and the Mavericks installer in your Macs Applications folder. Erase the USB stick with Disk Utility and call it (for example) “Mavericks”. Now open Terminal and copy & paste the following Terminal command and press the Return key:
sudo /Applications/Install\ OS\ X\ Mavericks.app/Contents/Resources/createinstallmedia –volume “/Volumes/Mavericks” –applicationpath “/Applications/Install OS X Mavericks.app”
Just follow the few steps and let it run. After a few minutes you will have a bootable USB stick with the Mavericks Installer on it. You can boot from the stick while holding the alt-key (or option-key).