I now own 4 rentals

Have owned them for awhile now

2 of the rentals, I have to constantly MEET the tenants for 400.00 dollars.. which is Only half the rent owed... then chase the other money down throughout the month

Same with the other tenant, at the other location. He pays when he feels like it. And it’s always in person, in cash.

How should I handle this?

@Charlie Moore

Have you considered hiring a property manager to be the bad guy?

Is the rent on those two at market? If not, you should raise it. 

Are they in a lease or month to month?

You should also switch them to a payment system such as:

https://www.paylease.com/corp/payment-processing/

https://www.dwolla.com

Cozy.co