A while back a friend of mine had a problem with water in the fuel system on his 4 stroke outboard engine. It caused major problems that took a while to sort – and at some expense.
This prompted me to look into fitting a water/fuel seperator.
Iv never had one fitted, but it turns out its prudent to have one particularly for four stroke engines and especially if you have an integral fuel tank.
The problems that can occur if water gets into your fuel system can be expensive to cure – and potentially dangerous if your engine fails whilst underway.
So with this in mind i searched the net for types of filter and found a decent looking one on a well known auction site – £47 delivered – and it included a spare filter – not bad considering the same items retailed at a staggering £180 at my nearest outboard centre.

The separator










This particular one has a clear bowl at the base so you can see any water settled there and a drain plug to remove it.
There were five ports on the top – three inlet and two outlet – and it came with three blanks for any not being used: 









I had to buy two 10mm barbs with 5/16 ends, six jubilee clips, and i replaced the priming bulb and all the fuel hose, as the existing was starting to degrade after six years of sea spray and UV rays. 7840 marine grade pipe and stainless clips were used for obvious reasons.

Next up was the location – somewhere out of the elements but as in line to the fuel system as possible – its not recommended that you increase the pipe diameter or lengthen the hose as the fuel pump on the outboard may not cope with the extra load placed on it – relatively modern engines are made to cope with pulling fuel through a seperator incidentally.
I had to modify mine slightly as the location was not quite vertical enough:

Look for correct flow direction








The actual fitting was straightforward – tank connector to filter inlet – filter outlet to primer bulb… look for the arrow indicating the correct flow direction – bulb outlet to outboard connector.
Under normal use it is recommended that the filter be changed anually.

The finished job. It’s up to you whether you fit one or not. Of course it is another expense you could do without, but ask yourself this. How much will it cost you when you get water somewhere in the engine? I know the guy with the problem had to resort to sonic drying in an effort to dry it all out. If your boat is not being used a lot, it could be safer to drain all the fuel out.


The finished job


COPYRIGHT: Wayne Comben. All rights reserved.