Fuel treatment(might be the right word?).

[Biker Biggles]

We used to put a bit of meths in the petrol to "dry" it.I think it just causes any water to mix fully with the petrol so it gets burnt off rather than sinks to the bottom of the tank or carbs.

Why don't you ask what people are using in the threads where they said they're great?

Because I could do with more than just one persons opinion, and I trust fellow bike people more than the ones with trainingwheels on. And someone posting with 3-6 posts in a car forum, could even be the seller, you never know, so I tend to ask questions more than one place, but it won't be on a car forum.

[yorkie_chris]

Possibly worth a look when you've a puddle in the carbs. Badly contaminated fuel though you'd probably need to add enough alcohol that it would screw with the jetting and such.

Maybe worth it as a just in case if you get stranded, get you to next petrol station where you ditch it and get some more.

I'd suggest a bowl/water trap type filter with a drain like on a boat would be better.

Originally Posted by speedyandypandy

[*]Water scavengers permanently solubilize and micronize water into fuel by creating a hydrogen bond between water molecules and fuel molecules...

Wow. I have never heard such a crock o' doodoo in my life... I'm a chemist and there is no damn way that you can hydrogen bond water (to any useful extent) to non polar organics (petrol, diesel, parrafin etc). This is why water and oil/fuel don't mix! No disrespect to you AT ALL speedy This is just a classic case of put some science stuff on the bottle and Joe Public will buy it. That product, like the Halford's stuff, will likely be a simple surfactant to disperse the water. Sorry for the outburst, this sort of stuff really grinds my gears

As others have suggested some IPA (maybe half a cup, 100mL or so?) will dissolve water in fuel to a degree, meths (methanol) would work but you have the problem of methanol's incompatibility with the sorts of plastics often used in fuel systems causing swelling of tubing, seals etc. if used regularly or left in the tank.

Another solution (or a preventative / long term measure) could be to use a package of silica gel desiccant in the tank (say 250g) and a bit of wire to fish it out periodically... I've not heard of this being done but often mused about it! Silica gel is essentially harmless, won't react with fuel in any way and absorbs something like half again it's own mass in water and can be dried in an oven above 150C. After letting the fuel evaporate of course! Woomph... You can even buy indicating varieties which change colour when saturated. Amazing.

Originally Posted by yorkie_chris

Possibly worth a look when you've a puddle in the carbs. Badly contaminated fuel though you'd probably need to add enough alcohol that it would screw with the jetting and such.

+1, from experience you'd need an awful lot of alcohol too - the petrol will solubilise the alcohol and kick the water right back out of solution.

This is the kind of answer I was looking for, thank you 85jas.
Knew there had to be a chemist hiding on this forum somewhere.

[yorkie_chris]

Originally Posted by 85jas

+1, from experience you'd need an awful lot of alcohol too - the petrol will solubilise the alcohol and kick the water right back out of solution.

I thought the alcohol being soluble with water AND petrol meant it allowed the 3 substances to mix thoroughly. Is this not the case?

So when IPA or something gets rid of water, is the water/IPA mix simply thin enough a fluid to get burnt as it is and never mix with the fuel?

Originally Posted by yorkie_chris

I thought the alcohol being soluble with water AND petrol meant it allowed the 3 substances to mix thoroughly. Is this not the case?

You're right that is definitely the case, but it's all about ratios - making up some numbers for a second if there's only say 10mL of water in 10L of petrol and you chuck in 100mL of IPA then you'll get a nice clear solution... but if there's 200mL of water in the tank and you put in 100mL of IPA then only some of that water will be solubilised, the rest will remain as a seperate layer. Some solvent systems (i.e. water/IPA) are fully miscible all the way through the mixture but many aren't.

e.g. Here is the ternary phase diagram for water / IPA / benzene mixtures.

It may look a bit complex but, just looking at the triangular diagram there is a bold line looping across the bottom. Below this line two layers (phases) form, above there is only one. For example point X is 25% benzene, 50% IPA and 25% water, that's a solution. Point Y is 50% benzene, 25% IPA and 25% water and that's not (two separate layers). Benzene is pretty good at taking up water compared to petrol (which does include benzene but is mostly other stuff) so for petrol that phase line will be considerably 'higher' in the diagram, i.e. less water is required to form a separate phase. If you had a diagram of say benzene, parrafin and IPA there would be no line as they all mix together in any proportion.

(I did look but couldn't find an IPA / water / VPower phase diagram )

Goes back to what you were saying about the jetting, if there's a lot of water (say 5%) you'd have to use so much IPA that it'd probably definitely throw out the fueling!

Originally Posted by yorkie_chris

So when IPA or something gets rid of water, is the water/IPA mix simply thin enough a fluid to get burnt as it is and never mix with the fuel?

It doesn't really get rid of it, just allows the water to mix fully with the fuel (more than would normally dissolve in neat fuel) i.e. no bottom layer of water in the tank / carbs!

Originally Posted by speedyandypandy

This is the kind of answer I was looking for, thank you 85jas.
Knew there had to be a chemist hiding on this forum somewhere.

Lurking about waiting to pounce on bad labelling You're welcome.

I hope the above makes sense

[yorkie_chris]

Originally Posted by 85jas

It doesn't really get rid of it, just allows the water to mix fully with the fuel (more than would normally dissolve in neat fuel) i.e. no bottom layer of water in the tank / carbs!

Ok it lets it mix and the big noisy metal thing underneath spits it out the back


Problem I have is on an XJ900, the bottom of the tank is below the fuel pickup (duh!), so water that gets in there by condensation stays in there and rots the tank out!

A small dose of IPA every few tanks to let this burn off seems like just the ticket.

Have you considered turning the bike upside-down and shaking it instead?