I hit 100% cash on cash return on all these B or C areas and they often outperform my better neighborhood properties. 

You are not even scooping your initial investment so your cash on cash return is negative.

If he doesn't need the cash now, you could also negotiate a split you're comfortable with to get him the return you and he feel he should have at the point you refi when the balloon payment comes due. 

Usually you have to pay for the privilege of getting a return phone call from an attorney.(9) We have over 30,000 of uncollected judgements on six cases and like the LA fires, try to forget about getting back what you had, move on and take precautions never to get into that situation again.

Best bet would be a “partnership” with a monied individual looking for a high risk/high return passive investment with you providing the “active” part.  

The bank does still ask for my tax returns each year and with each deal and my adjusted gross income last year was comparative to your stated cash flow from your rentals.

While this would not necessarily result in immediate taxes (because it can be offset by your lifetime gift and estate tax exclusion), a gift tax return (Form 709) would need to be filed.

Meaning, the bank wants to see that a property cash flows for typically one to two years of tax returns before they count it as income. 

Selling the property within your Solo 401(k) and returning the proceeds to the account simplifies compliance and ensures tax-deferred growth (or tax-free in a Roth Solo 401(k.)).

Getting a loan to payoff another loan with a lower interest rate doesn't make any sense. we do private lending and can get double digits returns consistently.