Everyone has made valuable points, but I would use caution before risking "The farm" on your business. There is no question you are going to be more motivated if your hungry. This is a business, and you have to make sound decisions. Later when you are making money for yourself someone is going to come along with an amazing new way to increase profits and they will have no problem trying to make you risk an even bigger "farm" just one more time. Always have a back door no matter what. Planning is the key to longevity. I have an older 21" walk behind in the shed I may never use again, but I keep it because worst case I can still mow for a day with it. I don't want to offend anyone or say that jumping is bad because that back door might just be as simple as keeping up friendly communication with the job you have now, so if it all goes south you could ask for your job back.
Good luck and go for it with all you've got, but never limit your options.