Engine mounted fuel filter

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Dave

I purchased a 1996 C30mkIII with a Universal M25XP engine this spring and as part of the commishioning, I changed all the filters and the oil. I put about 60 hours on the engine and drained the Racor fuel filter bowl several times with never more than a tablespoon full of water and "Stuff". About half way thru the summer, I also took the tank sending unit out and used a hand pump to suck out the bottlom of the tank, got about a pint of water and "stuff". The Racor is a 220RS with a 2 micron element, placed before the fuel pump. (I also cleaned the screen in the fuel pump this spring) My question is, is it necessary to change the engine mounted fuel filter again this fall, if it has a 2 micron filter ahead of it? Part two of the question is that the electric fuel pump seems to only run when the key is in the pre-heat position and is not pumping in the run position or on position. Is this normal? Engine runs fine. Thanks in advance. Dave
 
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Pete

ffuel filter/pumps

change the fuel filters both engine mounted and in-line (if you have one). It is cheap insurance for a problem free sailing season. The fuel pump will work "on demand " to keep a pre set preasure that is why you only hear it when first turning the key on the "pre heat" position then the pump will only come on as needed (the intector pump hold the preasure) so to answer your question Yes this is normal! Hope this helps! Pete
 
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Gordon Torresen

Fuel filter and pump

I would agree with Pete that you basically cannot change a filter too often. However, there comes a time that common sense must take over. Your two micron filter will stop a lot more than the engine mounted filter, therefor the engine mounted filter will stop nothing that gets to it. Less frequent changes are warranted. Finding water and stuff in your primary filter means that there is something in the tank. You sucked up the bottom of the tank so hopefully you now get nothing in the primary filter. If you do, you gotta suck better. As to your fuel pump, what you experience is normal for a late model M25XP, but not for the reason given by Pete. Your fuel pump is wired through a normally open oil pressure switch. The glow plug switch by passes the oil pressure switch to make the fuel pump run before starting. Let go of the glow plug switch and the pump stops. Start the engine and the oil pressure switch takes over and power gets to the fuel pump which clicks continually. The reason for this circuit is to shut the fuel pump down if the engine stalls(or is not running), a logical and good safety feature.
 
Jul 1, 1998
3,062
Hunter Legend 35 Poulsbo/Semiahmoo WA
Re: "Stuff"

There was a red flag mentioned called "stuff" that showed up in the fuel. After thirteen years of operation I've had practically no stuff show up in the sediment bowl of my Racor 2-micron filter (my engine filter is a 10-micron). On the ohter hand I've waited too long to change filters on occassion and noted some dark or black stuff on the filter element which was an indication that something was being picked up or growing there. After the filters were changed the engine did seem to run better. I think it was a really good idea that you pumped out the tank the way you did. A recommendation, if you don't already do it, is to use some biocide in the fuel as this should keep the critters at bay. And with regard to another item, the electric fuel pump (don't know if this is the only fuel pump you have or if there is an engine mounted mechanical fuel pump), and this is also a question for Torresen Marine, if the engine becomes a 'runaway' engine, is it possible to stop it by turning the electric fuel pump off? My concern is that since there has been stuff in the tank/fuel it is potentially possible that the fuel return line could have crud building up on the inside which could constrict the return fuel to the point of creating a runaway condition.
 
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Dave

thanks again

Gordon and John: Thanks for good info. Sediment bowl has been clean ever since I cleaned the tank. Gordon, the oil pressure switch makes a lot of sense. Thanks again to both of you. Fair winds Dave
 
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