I own a single family home in Valley Village and I owe 150K on the property and my pay off date is in 9 years.

If you pay on the back end, find out if they are adding the points to the principal of the loan - if they are you will be paying interest on that as well as the principal amount.

Total Payment: $2000/month ($800 going to principal)2) Have no roommate: This would be preferable however I'd be paying close to $3400/month ($800 going to principal).

And the numbers, based on the listing are:-list price $177K-10% down payment $17,700-monthly mortgage with 10% down is $943.00/mo -closing costs estimating $2K-$3k-property management fee I don't know-property tax $74.00-principal and interest $737.00-home insurance $49-mortgage insurance $83.00-rents for $1,850-$1,950/mo -cap ex budget I don't know-utilities I don't know-vacancy based on the listing it has been on the market for 148 days

He believes I still owe him 45k to receive the 90k he put into the house to make it “equal”.

I currently owe 215k in student loans (new doctor).

Bought it for 78,000 owe 65,000 on it now, and it rents 1600 a month.

Again, you have to pay this back with bi-weekly equal principal & interest payments otherwise you'll have to declare income tax and pay a penalty. 

Please be sure to select a Solo 401k plan provider which allows you to take a loan and will prepare the required 401k loan documents.The repayment terms are equal monthly/quarterly payments (as you prefer) of principal and interest (e.g. prime + 1%) spread over a 5 year term (or longer if you will use the loan to purchase your primary residence).

So, if they are collecting interest, they will have to pay income tax on it, but the principal portion of each monthly payment is tax free.