Myford ML 7 R

Hello I have just purchased a ML7R and I seem to have a problem with the lathe tools.
It has what looks like a standard tool post for 4 tools, I put in one of my 10mm tools in but they are sitting to high does this mean that I need something like 8mm tools.
I am a complete novice and though thicker tools were more stable.
What are the standard tool size for this lathe.
Many thanks
Dave.