LTV % of prior mortgages vs. new mortgages

[Reaz H.]

I've been looking through previous threads with regards to "second mortgage" but haven't found exactly what I am seeking so I thought I'd start asking. I would like to learn more about how lenders view the following situation and how to best navigate the process:

Say I have a property (that I live in) that I purchased with a 5% down conventional loan. It's a relatively new purchase so I still have approximately 5% equity. Granted I could have gone with a 20% down payment but it wasn't improving my low (~3.7%) rate. I would be saving on interest. I can always pay it down faster if I have no better alternative for deploying the cash. 

So that brings me to the next stage of the scenario. I would like to purchase a multi-family property and rent it out. Provided I find the right deal, I can make up ~15% return on the investment. I would want to go to a lender to get financing for the new property. Keeping in mind that I already have a property with 5% down would I have difficulty securing financing even if I put down 20-25% down? 

Or should I pay down my existing mortgage till I have a 80% LTV on it? I have the cash to do that, but if I do so then I lose the opportunity to buy more than 1 MFA using my own money. Will lenders balk at me not having enough equity on my primary home? I would like feedback on the factors that I have to consider.