How do I get water out of the fuel tank?

**carbonhed** · 4th March 2012, 17:34

I replaced the fuel cap on my track bike with a simple screw in type. Damn things not watertight. I've ripped the tank off and removed 99.5% of the fuel but there's still a film around the inside of the tank. I've thought of just leaving it in the sun with the cap off and letting the warmth evaporate what's in there and I've also wondered about blasting compressed air through it periodically... but I'm worried about static electricity and blowing my head clean off.

Any thoughts?

**Ocean1** · 4th March 2012, 17:38

Originally Posted by carbonhed

Any thoughts?

Chances of a mixture aproaching lower explosive limit isn't high.

I'd bung a couple of hundred ml of alcohol of some sort, (meths will do) shake it around a bit, dump the mixture and then stick it out in the sun to dry.

**BMWST?** · 4th March 2012, 17:39

leave it in the sun withthe cap off.when you are using the bike pour some meths in to the tank when there is a good ammount of petrol in there(ie no more than 10 percent meths by volume),the meths will absorbthe water and it will pass through the engine/fuel suystem harmlessly

**jellywrestler** · 4th March 2012, 17:54

meths a couple of cups will be fine and just use the biike as normal, meths is a fuel, methanol actually and like has been said it will absorb thge water and burn

**FJRider** · 4th March 2012, 18:51

Just put a few litres of petrol in the tank. Splash it around a bit ... then drain again. Whats left wont be worth worrying about.

**carbonhed** · 4th March 2012, 18:54

Outstanding. Thanks very much guys.

**yungatart** · 4th March 2012, 19:24

Isopropyl Alcohol is the best stuff, if you can get hold of it.

**scumdog** · 4th March 2012, 19:33

Originally Posted by BMWST?

leave it in the sun withthe cap off.when you are using the bike pour some meths in to the tank when there is a good ammount of petrol in there(ie no more than 10 percent meths by volume),the meths will absorbthe water and it will pass through the engine/fuel suystem harmlessly

Did an experiment a year or so back.

Put a litre of petrol into a plastic coke bottle.

Added about an egg-cup of water

Added about three egg cups of meths

Shook the whole lot up and it appeared all three had dissolved into each other.

Five minute later thay had all separated into three distinct different layers.

"Your results may vary"

**FJRider** · 4th March 2012, 19:38

Originally Posted by scumdog

"Your results may vary"

Wont be by much ...

**Ocean1** · 4th March 2012, 19:42

Originally Posted by scumdog

Five minute later thay had all separated into three distinct different layers.

In theory Meths, (actually mostly ethy alcohol) is infinitely miscible in water. It may be that the three layers you saw wern't the original three ingredients, not sure.

**Flip** · 5th March 2012, 18:02

The other thing meths does is it forms a semi stable emulsion with the water and the gas, this will be the middle layer.

To get the water to dissolve in the fuel you will have to add more meths than the rubber in the fuel systems can handle.

Simply drain the tank, add some meths, slosh it around, drain and refill with fresh fuel.

**BMWST?** · 5th March 2012, 21:00

Originally Posted by scumdog

Did an experiment a year or so back.

Put a litre of petrol into a plastic coke bottle.

Added about an egg-cup of water

Added about three egg cups of meths

Shook the whole lot up and it appeared all three had dissolved into each other.

Five minute later thay had all separated into three distinct different layers.

"Your results may vary"

too much water not enough meths.....