Do you need the supplemental income in the form of cash flow to survive. 

Everyone can have virtual training, but that should be your supplement, not your primary method.2. 

@Nicole Heasley & @David Robertson - Thank you both - Although this book is a fantastic read cover to cover - it does not supplement hands on experience.

There are those who simply want a little supplemental income who tend to have inconsistent revenue because they don't really treat it like a business.

If none tell them you will be raising to market rent but allow them 60 days to move and for you to find better tenants without a vacancy.If you are restricted to $100 then 4 years is way to long to wait to get them to market and you will need to give them both notice to non renew.Assuming you are investing to make money you must make the proper business decisions and frankly giving up thousands of dollars of income by supplementing tenants rents is not the way to do it.

I want to own them free and clear to supplement retirement income.

Keeping in mind I need about $1500 cash flow to supplement my primary residence mortgage, I'm trying to figure out what to do. 

I DO not need to access my cash or get my money out in the near to medium term.Although I'd love to supplement my monthly income, if forced to choose, I'd prefer long term growth over immediate cash flow improvement.Here are some things I'm considering:Replacing my residential mortgage with a first position HELOC and aggressively paying that down. 

Some people supplement their income very well by doing live in flips and live there for 2 yrs then sell. 

I will reach out to a wholesaler.Paying rent to my self is better than my current situation, but I don't want to to get stuck living in a 4plex supplementing the other 3 units because the numbers don't work.