Fuel/Water separator

murphy1

Seaman Apprentice
Joined
Jun 18, 2004
Messages
37
I have a 1987 DT200 and yesturday it stalled and I noticed the fuel primer bulb collapsed and cut off the fuel to the engine. I just replaced the fuel filter which is type that looks like an oil filter (about 15 gallons ago). I think it is a mercruiser brand system. Do these filters absorb so much water that it cuts off the fuel supply eventually? I bypassed the filter and had no troubles. Also, is there a check valve in most fuel tanks? I thought something might have clogged the pick up, so I blew compressed air into the tank and I couldn't get any in. So I put a vacuum on it and it sucked gas out fine. Any ideas?
 

WillyBWright

Fleet Admiral
Joined
Dec 29, 2003
Messages
8,200
Re: Fuel/Water separator

There is an antisyphon valve where the hose meets the tank. It's essentially a check valve.<br /><br />The filter shouldn't stop fuel flow even if it gets a lot of water in it. If it gets full of water, it'll pass the water. I've never known one to clog, way more filtering material than would be needed in the worst of conditions. Maybe it was defective. Or you have a whole lot of crud in that tank. I assume it's the right filter or it wouldn't fit.
 

murphy1

Seaman Apprentice
Joined
Jun 18, 2004
Messages
37
Re: Fuel/Water separator

I was told with those mercruiser fuel/water separators, there are only 2 filter styles, each with differnt thread sizes, so you couldn't mix and match by accident. The dealer told me there's a material inside that absords the water, as compared to the drainable separators that have a transparent base so you can see the water sitting at the bottom of the filter. So I was curious as to whether the filters material would absorb so much that fuel wouldn't be able to pass. I'll replace it anyway, but I just wanted to see if anyone else had a similar problem. It's a used tank, so who knows what's inside, thanks for the insight
 
Top