Re: Water separating filter for 90 4-stroke
A few points to consider: A water separator is never a "bad" idea but I question the need for one given the boat you are operating and the configuration of your fuel tanks (portable units stowed under a covered pilot seat). If there are known issues with water in your local fuel supply, you should install a filter by all means. If not, and you don't intentionally spray water around your fuel caps or leave the tanks out in the rain, there is less of a need for them. Your engine has a factory fuel filter with a little red ring that will alert you to the presence of water. You should check this filter often to make sure that red ring is sitting at the bottom of the filter housing and not "floating". <br /><br />A random data point for you to consider: I have the very same boat and put 160 off-shore hours on it (one season) without a water problem in my fuel. I never run straight gas and alternate adding Merc Fuel System Cleaner and Merc Quick Kleen in my fuel. Not so much the Kwik Kleen but the Fuel System Cleaner does have some water absorption ability and I am convinced that has helped a bit. I did finally install a water separator a few months ago for added peice of mind but I have never seen any water in it at all.<br /><br />NOTE: If you had below deck fuel tanks, I would not be giving you the above advice but you don't and as such, can avoid some of the water-in-fuel issues those guys sometimes face.
