You will need to put money into the deal, they will call it "skin in the game". 

They often hold the note themselves so they'll want to ensure you pencil out, the property pencils out, and that you have skin in the game.

I know it is always somewhat of a gamble, but you have to get some skin in the game.

A prudent seller will often require some down payment to ensure the buyer has some skin in the game.

If you had a lot more money/skin in the game you would stand a better chance.....  

In theory this is correct.. but in CA ( and all states are different) it could take you 6 months to evict them so that's six months of payments your making.. the could leave you a 5k mess ( pretty common in a eviction scenario).. and usually when folks starting out do this with limited capital when they make money on these deals they DONT save it they will spend it  LOL.. this is partly what crashed the market last decade.. investor with little to no skin in the game and no where near enough capital reserves.. any business with out proper reserves is destine to failure. 

Most hard money lenders will only lend 60-70% or less of the LTV  of the after repaired value and may want you to have some skin in the game. 

In fact, I rarely even bother asking why they are selling because a) I don't care, b) often they won't be honest with you anyway, and c) sometimes you just don't want to know (as was the case on an ex-hoarder's house I once bought, because the details would make your skin crawl). 

@Nick Zocher The fact that you have no skin in the game, and thus nothing to lose if you don't honor your side of a legally binding agreement, is what is raising flags for your seller.

If you have a property under contract, you can get money through a private lender, but they do want you to put some into the deal so you have some "skin in the game."