Purchasing a multifamily property that isn't 100% rented?

Is it a red flag when purchasing a multifamily property (in my case a 4plex) when only 1 of the 4 units is occupied? When I asked the seller why the other 3 units aren't rented, he said he wanted to be able to show them.

Is this a red flag? The units (except the rented unit) are all pretty much identical.

This property would be owner occupied also.

Thanks!

EDIT: Forgot to add that the one renter is Section 8.

I do not know about others, but it would be for me. So, it is simple to test that line of wanting to show the property. Look at the records for the past occupancies. How long have the places been vacant? I would have the properties inspected by a reputable firm to ensure there are not any hidden problems. You want to look at amenities there and how much you would have to invest to make the properties ready for occupancy? How much is rent in the area, what is the average income in the area, crime rate, and local community facilities and so on.

I would be a little hesitant just based of the information you gave. There is no reason on a four unit building to have 75% of the units open to show. Most smaller communities (200 or less) don't even have full time model units. I would want to truthfully know why the other units are open. It could be as simple as poor management which might be a great opportunity for you. I would stop over and talk to the current tenant, they probably know a lot of information on what's going on.