May be interesting to know the followings
If you're talking about the filter between the gas tank and the engine,
if the main purpose or concern is to separate water from fuel
if you're tired to buy expensive metal bowl cartridges, you can buy this kind of water saparator one time only (from LS, picture of the middle)), not cheap, the first time but after not necessary to buy extra cartridge, and you can see trough the bowl too. http://www.ls-france.com/ls/uk/distribution.php
but if the goal of filter is to clean the gasoline at 10 or 25microns the system is not for you.
mercury water separating fuel filer 35-802893T is 25microns
but Racor water seaprating fuel filer 35-809096 is 10 microns!
So just choose the good level of filtration in accordance with the engine spec, when you swap cartridges.
if the BRP fuel filter separator reference is BRP-502906 it's 25microns
the description is:
Fuel Filter / Water Separator Kit for all Outboards and Stern Drives, Replacement Spin-On Filter, Requires 1/4 Inch Male Pipe Thread Fittings (not included)
So all outboard
means premix and non premix for my understanding...
here a discussion on the same problem:
hope that helps