Water in petrol tank

ahutcheon

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Went to fill up when riding in the rain last week, and when I opened the petrol cap I was treated to the sight of water running into the filler neck. I've since cleared the drain hose (need to remember to do that regularly, not be reminded by a waterfall), but that still leaves the question of what to do about the water in the tank. I can't find any of the "dry fuel" additives (probably isopropyl alcohol?) locally, so I'm pondering other options:

1) Drain the tank and dry it out. Not keen, involves a fair bit of work.

2) Tip a litre or so of ethanol (OK, meths, but it's mostly ethanol) into the tank to mix the water and petrol.

3) Ignore the whole thing and just keep riding.

I'm leaning in the direction of 2), since the bike (2003 1150GS) should run on up to 10% ethanol and I'd be around 5%. I'd look for a fill-up with an E10 blend, but the nearest source is probably 1500km and a three hour ferry crossing away... There's lots on the internet about water in ethanol (meths will be around 4% water, E10 should be dry) and phase separation curves, but it's not clear whether any of this is a problem in practice.

So, any opinions (or ideally actual experience) of:

a) Mixing some meths with the fuel and the bike blowing up (or not)?

b) Ignoring the water and the tank later rusting through (or not)?

Thanks!
 
Golly, who knew?

WD-40
It may sound a little unorthodox, but WD-40 will remove water from your gas tank. Put one ounce of WD-40 per gallon of gas into the tank before filling it. The name WD-40 means water displacement fortieth attempt. Norm Larsen invented the product in 1953 to prevent corrosion by removing the standing water that causes it. His fortieth attempt was successful, and so the product is called WD-40.
 
I would have the tank off and empty it, put a litre of meths in, swill it around and empty that too. Replace fuel filter, replace tank, fresh petrol.
 
As Gadget says, or if you have an LED 'snake light' (ie no naked flame!) with the filler removed and the tank off, you'll likely be able to see where you can get the water's pooling. Length of plastic tube and you can suck/syphon it out.
 
Not sure where you are and what access you have to bits etc.

If you can get hold of some descecant silica gel (it can be found in small packets that accompany tools etc to stop them rusting).

Filter the meths through this it should, if still active, remove the water.

If it is not active then stick in an oven at 100 Centigrade and it will reactivate (open the packet first incase it catches fire).

Put meths and fuel in tank and shake.

then drain through fuel tap , again through this silica gel, into container.

Let it settle so thaat any remaining water ( if any) settles to the bottom.

Reuse fuel, discarding that at the bottom of the container.

This latter stage can also be done by putting the whole container in the freezer.

Water will freeze but the fuel needs to go much lower so will remain liquid -(just pour off)
 
Had the same thing with water getting in through filler cap - cleared the drain and forgot about it. I (maybe mistakenly) thought modern fuel had a percentage of ethanol in it so imagined that would deal with problem.... anyway when I changed the filter before I'd noticed the problem there was no sign of rust or water present so not going to worry about it.
 
Wasn't there a similar thread a few weeks back on here? I got a feeling that a few folks recommended using Wynn's or something from Halfords.
 
Put the meths in and forget about it.

What was all that about silica gel, I thought that absorbed moisture from the atmosphere, not water when filtered through it. I would imagine it would be fully activated after a very short time. Have you actually done this and did it work or is it the usual internet waffle. :beer:
 
karlp said:
Not sure where you are and what access you have to bits etc.

If you can get hold of some descecant silica gel (it can be found in small packets that accompany tools etc to stop them rusting).

Filter the meths through this it should, if still active, remove the water.

If it is not active then stick in an oven at 100 Centigrade and it will reactivate (open the packet first incase it catches fire).

Put meths and fuel in tank and shake.

then drain through fuel tap , again through this silica gel, into container.

Let it settle so thaat any remaining water ( if any) settles to the bottom.

Reuse fuel, discarding that at the bottom of the container.

This latter stage can also be done by putting the whole container in the freezer.

Water will freeze but the fuel needs to go much lower so will remain liquid -(just pour off)
Click to expand...

this magic is very potent but a bit daft. just throw the fuel away if you are bothered. Can you explain this in English!:hide
 
I wander if you would really be happy unless you confirmed you had got most of the water out. For my part I wouldn't be happy at paying money to throw products in the tank to get rid of the water, when all I had to do is drain it, take it off the bike remove the filler cap assembly, up end the tank to get the undrainable fluid out. Reassemble jobs done. Apart from waiting for the tank filler seal to dry out so you can refit it, the job should take no longer than 30min.

Simple and cheap, done it before, and I would do it again anytime.
 
Its simple really just drain the tank (via the reserve tap if it's got one) into a large glass jar. The stuff on top will be petrol anything under a separation line is water. Once you have clean petrol flowing, the remainder can go into jerry can(s). You can add some surgical spirit if you want to be 100% sure no water can get into the carbs/injectors.

Then sort out how water got into the tank in the first place.
 
Bendy toy said:
Its simple really just drain the tank (via the reserve tap if it's got one) into a large glass jar.
Click to expand...
:eek:

Then put it in the freezer, add a bit of meths give it a good shake and then take it to your local Recycling Centre... damn, forgot the Silica Gel :blast
 
As the OP I want to throw in:

Looking a bit more closely at phase separation curves suggests that meths (ethanol) won't safely dissolve much more water than it already contains at the 10% mix that BMW claim is safe for the fuel system. Probably why E10 petrol uses anhydrous ethanol, the water content left by distillation would risk separation at low temperatures. If I guess at 100ml of water having got in, draining it out is the safest way to go.

I've cleared the drain to stop recurrence, just need to run the tank down as far as possible and drain the remainder sometime convenient.

As for Halfords, who needs them when we have SuperCheap Auto?

And riding back out of Golden Bay over the Takaka Hill in the dry was well worth both the soggy ride in and the water in tank woes. An evening in the Mussel Inn was a bonus.
 
Bendy toy said:
Its simple really just drain the tank (via the reserve tap if it's got one) into a large glass jar. The stuff on top will be petrol anything under a separation line is water. Once you have clean petrol flowing, the remainder can go into jerry can(s). You can add some surgical spirit if you want to be 100% sure no water can get into the carbs/injectors.

Then sort out how water got into the tank in the first place.
Click to expand...

Reserve tap?
You do know we're talking about fuel injected BMW's?
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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