a lot of new investors run rosy numbers, see that they'll get $250 a month in "cash flow," and then they have to replace a furnace (in a single family) or a huge roof (in a multifamily) and that "cash flow" is gone for years. 

Have the opportunity to purchase 64 homes, all have renters, book of business is very profitable. 90% of the properties have new roofs.

Roof, HVAC and foundation all have no issues.My plan with a property like this would be to get positive equity asap and re-fi.

Will you be required to inject capital if they need it to repair roofs / foundations / plumbing / etc. 

You want every single nook and cranny of the basement, as much of the roof line as can be seen, the entire property lines and grounds, the road in front and neighboring 8 houses.

BP fam what are your thoughts on my scenario -- I bought my primary home for $335k 2 years ago and have put about 40k in upgrades (new double paned windows, new foundation, new metal roof, rain gutters).

(Note: These are non-negotiable requirements) Other Incentive ProgramsSmall Business Improvement Fund: Best thought of as a storefront/small business rehabilitation program, this small grant program ($150,000 for commercial properties and $250,000 for industrial properties) is targeted for smaller renovation projects and can cover anywhere from 30-90% of the cost of remodeling a storefront facade, roof replacement, major systems replacements (HVAC, plumbing, electrical, etc.) or an individual interior space build-out within a larger building to get it tenant ready.

I have a roof leak.

You buy at a small price thinking high cash flow yield but then do not factor to renew tenant will likely want new roof, parking lot, etc. at hundreds of thousands of cost.

If you don't have a primary residence yet, I would highly recommend house hacking first.This is a great strategy to use low money down, get into an investment property, have a roof over your head and still keep a large portion of that inheritance.