Can I file a list pendence against my soon to be ex-partner over a property that I didn't not want to be put on title but we carried the property in our partnership as equal owners?
If so, can I file without a lawyer?

You can file a lis pendens against a piece of property if you are planning on immediately filing a lawsuit concerning that property. You can file the lis pendens yourself but keep in mind that the lawsuit must be filed immediately and if you make a mistake in filing the lis pendens then it will be ineffective.

I suggest that you immediately speak to an attorney rather than attempting to do this yourself.