Problem with Tiger install on G4 using Target Disc Mode

I'm attempting to install Tiger on older G4 without a DVD. I'm using an eMac in Target Disc Mode -- with the Tiger install disc in DVD drive -- to do the installation. However, I'm running into a problem.

I can set up the eMac in TDM without a problem. The G4 sees the eMac and Tiger install disc. Contents for each volume are visible in the G4. However, when I attempt to reboot the G4, the computer boots from the internal drive. I've tried option boot...no luck. In the 'Start Up' option in the G4 control panel, the eMac and Tiger volumes are listed, but they are grayed out. I cannot select them.

The G4 is a PCI graphics model running OS 9.2.2. I've checked firmware on each computer. Each is up-to-date.

Have a read of this Apple Discussion Link and as stated PCI Yikes models were not Target Disk Mode capable:-

Apple - Support - Discussions - Installing Tiger on G4, OS 9.2 ...