Symptoms of water in fuel ?

[PeterM]

Been out with a mate this morning in his new to him SIB with a 15 Yam on the back. ( ok ok I know I am suppoesed to have day/desk job ! )

Was fine but then started loosing power and surging & was like this for maybe 2-3 mins across the rev range , no misfire just a lack of 'go' . Cleared up for 20 mins , then came back for a few , then fine until we came back.

He stores it outside and I reckon its got water (condensation) in it and its was this that has caused it . He is adamant it wont have water in it.

I've always run with seperators so have never had the problem of water, but it seems to make sense to me.

Any comments / suggestions ?

[willk]

i fink yor fute waz onn de petril hoze

[Dry Run]

Run it on a remote tank with "clean" fuel and see if the problem persists?

[jyasaki]

Portable fuel tank? Empty it and take a look.

jky

[Peter_C]

Usually a bright flashlight into the tank shows if there is water or not. Also drain the carbs into a clear glass container, and again look for water. Often water is very obvious.

[Poly]

Originally Posted by Peter_C

Usually a bright flashlight into the tank shows if there is water or not. Also drain the carbs into a clear glass container, and again look for water. Often water is very obvious.

petrol vapour + potential for spark !

Originally Posted by PeterM

...new to him SIB with a 15 Yam... He stores it outside and I reckon its got water (condensation) in it ...

unless it came with water in it, or he's left the vent open in a position that gathers rain I'd guess it probably isn't water. It takes a long time sitting in quite cold conditions to generate enough condensation to cause a problem; its minimised with plastic tanks, keeping the vent sealed and keeping the tank close to full.

Was fine but then started loosing power and surging & was like this for maybe 2-3 mins across the rev range , no misfire just a lack of 'go' . Cleared up for 20 mins , then came back for a few , then fine until we came back.

I've never had water in my fuel, but that isn't what I would expect - i'd expect it to die completely and probably not recover until fresh fuel or carbs drained etc.

Originally Posted by willk

i fink yor fute waz onn de petril hoze

There speaks the voice of experience. And I think you might be on to something though...

[Peter_C]

Originally Posted by Poly

petrol vapour + potential for spark !

Ummm...who buys flashlights that aren't completely sealed and waterproof? All mine are double o-ringed. Spark is a non issue.

Quit a few good points made though. What about something stupid silly like not opening the vent cap? Not that I have done that less than twice

Drain the carb and see what comes out!

FWIW storing fuel tanks full is the best way to keep condensation from forming inside and letting it drip into the gasoline.

[captnjack]

It doesn't even need to condensation or changing temperatures, the added alcohol will naturally absorb water from the atmosphere. And fuel sometimes comes with contaminated with water from the pump. Or could be old fuel too.

[Pikey Dave]

Originally Posted by Peter_C

Usually a bright flashlight into the tank shows if there is water or not. Also drain the carbs into a clear glass container, and again look for water. Often water is very obvious.

Or fit a Racor filter with a clear bowl, no torch needed & you can see & drain off the water before it gets to the engine

[PeterM]

Thing is has cleared itself....so I won't be trying to see into his tank by the light of a match. It's not the vent or me sat on the pipe.

I did drain the carb.bowl and our looks clean. Emptied the track and it had the smallest, like half a teaspoon of water In it. Just I really can't of what would cause the surge in a two stroke carbed engine.

It has to be fuel....any way the fuel pump could do this and create the symptoms?

[PeterM]

If you can understand my daft phone spelling well done!

[Peter_C]

Half a teaspoon of water could have been a full teaspoon or more before the issue.

[smiglet]

I have the same problem on my Evinrude 225 it happens at nearly the same place in the river each time i go out the engine struggles for fuel but if i squeeze the bulb a couple of times it clears it,its fine at high speeds but happens below 6 knots ! confused.com

[Peter_C]

Originally Posted by smiglet

I have the same problem on my Evinrude 225 it happens at nearly the same place in the river each time i go out the engine struggles for fuel but if i squeeze the bulb a couple of times it clears it,its fine at high speeds but happens below 6 knots ! confused.com

Fuel restriction? Fuel filter(s) could be plugged. Fuel pump may not be pumping enough. Along with anything else that could cause a fuel restriction or an air leak into the fuel lines.