I know what the purpose of a water seperator is but can someone explain to me how it works and how I know when to replace it and which type should I use for my 2002, 150, Johnson, 2 cycle engine? Thanks
I disagree, a 2 micron filter with racors and a bowl will work better on a HPDI engine then a 10 micron filter. It depends on the engine.seasick said:The 2 micron filter is no more effective at separating water than the 10 micron. It does filter out smaller particles of sediment, dirt etc. Water molecules are many many times smaller than 2 microns.
While it is true that separators work because water is heavier than gas and the water in the filter will drop to the bottom, if the flow through the filter is fast enough, the water won't have time to fall to the bottom. In addition,since the bottom of the filter only holds a few ounces, it doesn't take a lot of water before it passes through the filter.
It is reasonable to guess that a smaller boat motor will get better 'filtering' than a larger motor simple because the flow rate is less and the fuel 'sits' in the filter longer
Ethanol gas ( 10%) can absorb 0.5% water by volume. That water is burned off in the motor. Once there is more than 0.5% water, it will settle out to the bottom of the fuel tank. If it gets pumped throught the filter, any amount greater than the bowl volume will end up in the engine ( and that assumes that the filter got all it theoretically could)
For a 100 gal tank, 0.5% is 1/2 gal of water. The bottom line is that if you get a bad tank of gas with a lot of water, the filter isn't really going to make a difference.
That filter holds about 2 ounces of liquid. The main filter holds a lillte less than a quart. Their prupose is not to protect from a lot of water in the gas. They are there to filter out mild moisture/condensation. If you get a bad load of gas that has a lot of water, that ring will rise in a hurry. the motor will die before you have a chance to check the ring.Islander said:The "internal" fuel filter on my Yamaha outboard sits inside a clear plastic cylinder. It has a red ring float that sits on the bottom, but by design will rise or float up when water is present at the bottom of the bowl.
I assume that monitoring this float periodically will provide a warning that the external fuel filter is no longer effective at separating water from fuel. But I nonetheless change the external fuel filter per Yamaha recommendation.
Seahunter said:Its absolutely nuts to change filters based on calendar intervals. A filter’s replacement interval should be determined by a pressure drop in excess of motor manufacturers specification.
Do yourself a favor and install some sort a pressure indication device on the fuel line. Racor makes one that plugs right into the filer head. You can get a simple screw in for $50 or you can go all out and install a sensor the has a remote gauge that you can install at the dash. With filter costing $25-$25 apiece, it doesn’t take long to recoup the money for the sensor by not replacing perfectly service filter based on time.
merlin25 said:Seahunter - I've been looking for the Racor pressure guage and can't find one. Any advice on a place that sells one? Also what kind of pressure range are we looking at for the gauge?