That depends on your finances. Do you have the money to afford to quit? Sure you may be starting a business, but who's to say that business will see profit right away? Who's to say it will even succeed? I recommend you work a job until you are comfortably able to move on to your new business. Because if your business isn't going anywhere and you quit your job, then that's money down the drain essentially.
Work until you don't need to.
Work until you don't need to.