I bought it under my LLC and I have been thinking of refinancing.

You may be better off refinancing with a cash-out mortgage and then financing the new property.   

What about rate and term refinancing?

Have you refinanced this into a long-term mortgage?

Thought about refinancing at the time, but didn't do it before rates exploded.

So I have my house that refinanced in 2020 for a 15yr 2.5% rate and we have about 56k equity.

That way, you could use Hard Money to fully fund the rehab before refinancing to agency. 

Since my RE financing investor does the incentive of paying for the property, I want to make sure that my business partner is getting a great ROI in profits, so I want to make sure that money is working for the first investor making a deal with me in the smoothest way possible! 

Some lenders offer creative solutions, like a cross-collateralized loan, where they use your existing equity as security without refinancing the duplex.Another idea is partnering with private lenders or exploring a second-position mortgage, depending on your lender's terms.

Key Factors for a Good Seller-Financed DealCash Flow: Rental income should exceed monthly payments (PITI) by at least 1.25–1.5x.Purchase Price: Compare to ARV and market value for fair pricing and equity potential.Interest Rate: Aim for competitive rates; higher rates must still allow positive cash flow.Amortization/Balloon Terms: Favor longer amortization and align balloon payments with your exit strategy.Down Payment: Lower upfront costs reduce risk but should meet the seller's expectations.Flexibility: Seek no prepayment penalties and fair late-payment clauses.Property Condition: Ensure the property’s condition matches terms through inspections.Seller Motivation: Assess the seller’s willingness to negotiate favorable terms.Exit Strategy: Have a clear plan for refinancing or payoff at term end.Portfolio Fit: Ensure the deal aligns with your financial goals and risk tolerance.Vetting multiple deals and consulting professionals is crucial to making sound decisions.