Water in Fuel

[wasmeneh]

I have drained my on engine (Merc 200) fuel filter twice, and the on board filter once. On each occasion there was water present. Unfortunately I have a full tank of fuel at present. I plan on using a hose and sucking up the fuel from the bottom of the tank to see whats there.

I have a spin on type filter between the gas tank and engine, I would like to replace this with a Racor type so I can drain off the residue. Any ideas which one to look for ( The current filter is like a full size oil filter)

I think the water was being introduced by back wash but I added an Allison skid plainer this weekend so I don't think this will be an issue anymore. I also reversed the gas cap seal and now it fits tighter.

Any ideas?

Mike

 

[SLOmofo]

First fix the why water is introduced. Then drain the tank completely and put a couple of gallons in the tank. Pump fresh fuel through, blow it out again. If it's carbureted there's water in the carbs. Some times there is a main jet plug/screw that you can take out and drain most of what's in the carb out, most. Then use a can or two of brake clean or carb spray, spraying into the bleed jets. That may flush the left over water out the main jet plug. Safest if remove, disassemble the carbs. Blow out the fuel lines with compressed air.
Injected, pull the injectors and have them inspected and cleaned and flowed.
All this seems as overkill , but it way cheaper then pistons and sleeves!

Gas today(most gas) has alcohol in it. Alcohol will mix with water. Water by it's self won't pass through a small orifice like a jet. It will just sit on top of it and block it as the engine is trying to suck fuel through it. Can you say lean seizure. Alcohol that is combined with water will pass through a jet, but it isn't the same as just gas and the lean seizure will still occur.

What's in the tank?
Straight gas and water.
Gas with 10% alcohol and water.
Gas with 10% alcohol mixed to saturation with water and the extra water is separated in/on the bottom of the tank.

Oh! That mix of water/alcohol will stratify/settle out in the tank over time.
This is why you don't leave fuel for a long time in the tank. 1 it will loose octane and 2 if the tank can breathe it will draw in air that has water in it.