We wanted to keep it but decided to upgrade to a bigger house instead.

Being that the tenants have lived there a while, some of the units do need upgraded to justify a rate increase.

I’ve heard some people say that you can do small things like ripping up carpet to expose the hardwood or upgrading window dressings like curtains, but are there any other smaller renovation projects that have an oversized impact on the appeal of the property to your renters?  

As mentioned above a usual clean out and upgrade will be needed to jump rents this high. 

If you get inspections and make a checklist you can anticipate issues and fix or upgrade prior to placing a property on the rental market.

Understood that it would not be easy to get much of a discount on houses that don't require much rehab or are not "distressed" - but perhaps a bit run down and just need some cosmetic upgrades that would not require a long drawn out rehab? 

Flipping Houses Pillar 3: RehabbingThe 3rd pillar in operating a house flipping business is rehabbing.Rehabbing is the process by which you fix and upgrade a house to bring it up to “retail” value, so you can sell it for a profit.

@Stephen Wong If funds are limited, I would ensure that the property is clean, organized, and somewhat appealing on the outside, then concentrate the remaining funds on the inside until you can afford more exterior upgrades.

I’m not an expert on this, but I figured before I even bought that I might need to upgrade to 200A.

If they start complaining then that would be the time to give them notice and do your upgrade.