You should have one in line scavenging filter. Very questionable about the water - separator. If you do have a water - separating filter it would probably be mounted on your transom and be the approx. size of an oil filter.
It should look similar to this :
http://www.sportsmansguide.com/net/c...9&kwtid=300530
Now your stalling issue could be related to a number of things. When was the last time a complete tune up was done? How fresh is your fuel? Are those filter's clean and installed properly? Look for the arrows.
If all of those prove to be O.K. then you can take a look at your timing. etc.
( part of the tune up deal ) . There could be other things to look at but just start with the very basic stuff.
