Problem Fixed with pictures!!! Outboard 4 Stroke Engine Problem

[lokidog]

Looks like water contamination in there caused the crud buildup and probable air leak in the line.  A good reason to put some oil on that o-ring as well.  Congrats on figuring it out and saving a huge shop bill.

[Gobble Doc]

Oil on the o-ring is a good idea.  It sure seems to make sense that at higher speeds it was suckin air and causing engine to sputter.  I'm really going to try to get the ethanol free gas from now on.  I found the place in town that sells it. 

[lokidog]

Guess I've been lucky, I've never had problems with ethanol.  Knock on wood....

[Heredoggydoggy]

Probably just a plugged fuel filter.  Gasoline will pass through a filter, and water won't.  Get enough water in the filter=plugged filter.

Huh?  Water will flow just fine through a filter unless it is designed as a fuel/water seperator.  As mentioned by others, it sounds like you have some flow restriction.  I have a 9.9 that I had to drop the carb because it cut out on me at full speed.  It would then start  and run for only a few seconds.  It has a filter on the end of the fuel take up hose in the tank, and a filter where the fuel flows into the carb, but there was still a bit of silt like material in the carb bowl.  I pulled the jet out of the carb and couldn't see the hole so blew on it and pting, out popped a tiny, tiny bit of something.  If you have more than one carb you may have just one of them plugged, hence the engine runs at low speed. 

I have also had "varnish" in my gas line that had been sitting a while which could have been liquidized fuel hose or stuff actually from the gas, fresh gas would not dissolve it only acetone would touch it.  If your fuel line is older, I would replace it with one that is alcohol resistant, the bulb as well.  A neighbor spent a thousand or so because his fuel line's inner liner had disintegrated and clogged up his fuel injectors.  Spend the extra money for a high quality hose.

Also make sure your air filter, if you have one is clean.

Water will flow through some filters, and others it won't.  I think it has to do with the molecule size, and the density of the filter material.  I talked to one person that used a piece of equipment that ran fine until the fuel filter got water in it.  They got another filter, and it ran good again until the filter got water in it again.  They put the old filter back on, and it ran good again until the filter got water in it again.  They just kept switching filters back and forth, giving the water a chance to dry out of the idle filter.   

[Gobble Doc]

It makes sense to me that gas may not go through a filter once it is wet with water.  I have done a lot of filtrations in lab where I'm running an organic solvent such as gasoline through a filter paper with no problem.  Once the filter paper gets wet with an aqueous solution such as water then organic solvent will not readily pass through the paper if the 2 liquids are immiscible.  The water coats the paper and the organic liquid just doesn't go through (unless some pressure is applied to either push or suck the liquids through the paper).  So, if the filter contains some kind of high density pleated fiber then I can understand water blocking the filter.  If the filter is just some kind of coarse mesh plastic then I don't see that water is going to "plug up" a filter. 

All I know is that I'm going to empty every fuel tank on every engine I have and make sure that things are clean and dry before winter sets in.  Generator, weed eater, lawn mower, tractor, chain saw, pressure washer....