I discovered that it would take us roughly 7.3 years to break even on the 30 year loan, as we will be paying less principal and more interest, but ultimately getting rid of PMI.

I don't think I should count the missed principal payments as cash flow because that is in effect reducing my equity in my property, but what about the interest I would not be paying for those two months?

You didn't provide me with the interest rate so I just assumed interest at 5.140% off of the principal payment you provided. 

Lenders who have posted here care to comment.See belowLimits on the Number of Financed PropertiesIf the mortgage loan being delivered to Fannie Mae is secured by the borrower’s principal residence, there are no limitations on the number of other properties that the borrower will have financed.

. $800    rent- 400   all expenses other than you loan payments (50%)  *=400   Net Operating income-310    Mortgage payment, principal and interest only.   **  $90    Net bottom line monthly cash flow in your pocket.

Originally we thought they were just the debt collector but they served him papers for a judicial forclosure claiming he owed them almost double what was remaining on his principal due to back taxes and home insurance payments that I highly doubt they have been paying.

yes …. you can do it that way you can do a participation note... secured or unsecured.. the main thing is to have a conversation with the first lender let them know our a principal in the transaction and if anything happens you have the right to cure and take over...  

)                           -   Gross Monthly Operating Income              32,642.00 Monthly Operating Expenses Monthly Property Management Fees                   832.00 Repairs and Maintenance                1,000.00 Real Estate Taxes                5,241.00 Rental Property Insurance                1,959.00 Homeowners/Property Association Fees   Replacement Reserve                2,000.00 Utilities                1,291.00  - Water and Sewer    - Gas and Electricity    - Garbage    - Cable, Phone, Internet   Pest Control                   155.00 Accounting and Legal                   150.00 Advertising   Monthly Operating Expenses              12,628.00 Net Operating Income (NOI)   Total Annual Operating Income            391,704.00 Total Annual Operating Expense            151,536.00 Annual Net Operating Income            240,168.00 Capitalization Rate and Valuation   Desired Capitalization Rate 10.00% Property Valuation (Offer Price)         2,401,680.00 Actual Purchase Price         3,100,000.00 Actual Capitalization Rate 7.75% Loan Information   Down Payment            620,000.00 Loan Amount         2,320,000.00 Acquisition Costs and Loan Fees              60,000.00 Length of Mortgage (years)                          30 Annual Interest Rate 4.970% Initial Investment            680,000.00 Monthly Mortgage Payment (PI)              12,411.76 Annual Interest            114,527.10 Annual Principal              34,414.02 Total Annual Debt Service            148,941.12 Cash Flow and ROI   Total Monthly Cash Flow (before taxes)                7,602.24 Total Annual Cash Flow (before taxes)              91,226.88 Cash on Cash Return (ROI) 13.42% The property is being given to me after completing 40 year certification (updated plumbing, electrical, parking, most units are decently remodeled.

B. what happens when you inject more funds into the principal: does the end date of the loan reduced, or does the monthly payment go down?

Paying principal contributions on a HELOC sucks.