Bypass valve in fuel-water seperators ?

[rubberchicken]

I have an acquaintance with a boat that crapped out. They bypassed the main tank and used a 6 gallon portable tank, and that allowed the engine to run for a few minutes, and then it stopped again. Various tests point to bad fuel, or water contamination. It has the standard Mercruiser fuel filter with water separator . We are trying to determine if dirt could get past the filter into the fuel injection system. It is possible its just water contamination, or fuel phase separation. Does anybody know if these filters have an internal bypass valve like most oil filters ?

 

[CT8]

What various tests did you do to point to bad fuel? Did the 6 gallon tank have bad fuel as well ? Something seems to be missing in the diagnosis procedure. Did you remove and drain the fuel filter to see what came out of the dirty side of the filter? Is there spark after the engine dies? No bypass on fuel filters.

 

[rubberchicken]

The 6 gallon tank had good fuel, so water or dirt in the fuel is the primary suspect. That is good to know that there is no bypass on a fuel filter, BUT this style is built similar to a canister oil filter, at least on the outside. Next step is to empty the fuel into a clear container, then cut open the filter if water is not found.