2 Duplexes (4 Units) - How much maintenance / work expected?

[Jeff Howard]

Considering getting 2 duplexes and planning to self manage... was wondering what is the typical amount of work (answering phone calls for maintenance, other issues) that I would have per month. Maybe this is a better "per unit" question.  How much monthly involvement is there per unit typically?

Are we talking 1 call every couple of months, per unit?  I know this is a big "it depends" question, but I am sure there is a good ratio number that folks that have been doing this for a while on a lot of property would know.

Thanks