@Eli Rollins, if you stated in your loan that this will be your primary residence and owner occupied, it would be mortgage fraud if you decide not to live there.

The land is $410 a month, mortgage after rehab would be $350 a month.

And if a big bank won't give me another mortgage (no idea yet..), are there alternative options? 

I just want to figure out a way to tie in the repairs into the mortgage if possible.

If I take out a mortgage, my return goes down. 

JeffListing Price:$159,000 INCOMERental Income$1,748 $.85/sqft.Garage$0 Laundry$0 Storage$0 Misc$0 Total Monthly Income$1,748 EXPENSESTaxes, Property$350 Insurance$100 UtilitiesElectric$0 Water$100 Sewer$50 Gas$0 Garbage$0 HOA$0 Lawn/Snow$0 Vacancy$100 Repairs$100 "Capital Expenditures (i.e. new roof)"$150 Property Mgr $0 Mortgage $705 Total Monthly Expenses $1,655 CASH FLOWIncome $1,748 Expenses ($1,655)Total Monthly Cashflow $93 CASH-ON-CASH ROIDown Payment $15,900 10%Closing Costs $5,000 Rehab Budget$5,000 Misc, Other  $0 Total Investment $25,900 Annual Cashflow $1,111 Cash to Start: $25,900 Cash-on-Cash ROI 4.29%

They plan to live in the duplex and rent one side out to help with the mortgage, which means they don't mind paying more than half of the mortgage.

I owe 55k on a trailer double wide. (I know big mistake) should I focus on paying this off or just rent it out and let it be

If there was a mortgage on a house that got damaged there may an insurance claim that may be filed.

Also, if you have a mortgage, talk to your bank before transferring.