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Discussion Starter · #1 ·
So, when I got the bike the fuel line was already cut... Not sure why, too lazy to remove it I guess? But I noticed a thick yellow oil around the line that was odd.

Removed the tank today, used the pressure washer to clean the bike and see what's what. Expected the tank to be empty because last ran in 1989, but could hear some sloshing. Dumped out what was there and some gas, and about a cup worth of that yellow oil... Almost like cooking oil.... Came out.

Anyone know what it may be? Maybe oil to keep the tank from rusting when in storage and the fuel line cut as a precaution of trying to start it with that in there?

Next question, cleaning. Saw online where it was suggested to mix baking soda, vinegar and water as a good cleaner... Anyone try that or know of something better?

I was thinking of doing that, drain, then maybe toss a cup of rubbing alcohol in, slosh it about and dump it... May help it to dry faster inside.
 

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Saw online where it was suggested to mix baking soda, vinegar and water as a good cleaner... Anyone try that or know of something better?

I was thinking of doing that, drain, then maybe toss a cup of rubbing alcohol in, slosh it about and dump it... May help it to dry faster inside.
No idea what the yellow oil is, but I doubt the P.O. would have put oil in the tank.

Baking soda and vinegar strikes me as a bad idea. That will react to create salt in your tank.

I would clean with some kind of solvent - gasoline, paint thinner, etc. - until all the dried gas sludge comes out. A long soak and several rinses are in order.

After getting all the sludge out, if there's any rust vinegar will help dissolve it. Watch out for flash rust though. If you don't immediately coat the tank with oil after rinsing out the vinegar, though, flash rust will come right back.
 

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Discussion Starter · #3 ·
I never heard of the method before, was just Googling a few things online and came across the hit/miss eHow.com method

LINK

Didn't sound bad, but didn't seem like it would be strong enough for heavy sludge. I might try a paint thinner... is there a recommended one? Like acetone vs mineral spirits vs turpentine vs ...

I didn't notice very much rust... debated a chemical product, but, I try to be as green as I can and I have 10 litres of molasses here I was using to remove rust from car parts. Thought (once gas/mystery gunk free) I'd fill the tank with water/molasses and remove the rust with that. Sounds odd, but, check on YouTube, that molasses works and can just dump out because not a harmful chemical.

After done, I guess use some sort of fuel tank sealer...
 

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Discussion Starter · #4 ·
Found this today... mentions the gas becoming like vegetable oil, which seems pretty spot on for what I had.

LINK
 

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Discussion Starter · #5 ·
Bit of a delay but finally trying to clean the tank... Not much luck.

Sludge seems really heavy and thick, thinking of trying muriatic acid which seems !mentioned in many forums mixed 50/50 water. Thing I am noticing though is no mater how much I shake the tank, it always sounds like there is another cup worth of liquid in the tank sloshing about.

Any advice? Assumed holding upside down and shaking would be enough. Was going to throw some drywall nails in but worried they'll get stuck in there wherever the liquid is.

Originally I pressure washed the tank out, tank was clean almost no rust... Didn't realise how fast that flash rust would occur... So tried some CLR, see if can clean up the flash rust but noticed I was getting even more sludge out. Got a mild car grease cleaner and have in now but doesn't seem to be doing much.
 

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If the residue is from gas i would use carb cleaner or brake cleaner. Get the old style solvent based one from Princess auto with all the warning labels on it. Gas would probably work also but slower and not as well. Shake it around but most of the slime is probably low down in the tank so let it sit a while. Get some fogging oil spay from Cajan Tire or auto supply. When tank is cleaned out spay with fogging oil to stop the flash rust.

You will get more out by draining from petcock opening. Coller inside filler opening stops you from draining everything.
 

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Discussion Starter · #7 ·
I removed the petcock, it was all full of the sludge and kinda blocked, also lose so just turned out off by hand. Then duct taped up the hole.

I have a 5l jug of solvent from princess auto for cleaning parts, I'll dump a bunch into it... Need to get this stuff out before I do much else. Was thinking of the kits for cleaning/lining but didn't want to use it until the bulk of it is gone.

Never heard of fogging oil, will def grab some.
 

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Discussion Starter · #8 ·
Anyone try using molasses for rust? I used it on stuff like hammers, bolts, etc... I have about 4gal of it, mix 1:9 with water and fill it up, let it sit a week
 

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Discussion Starter · #10 ·
That's where I was hesitating... Especially with how hard its been to get what's in the tank out... Hoping the solvent works because was barely getting anything out of the hole where the petcock goes... So full of sludge.
 

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That is where a higher solvent like a brake cleaner will attack the sludge more aggressively than a degreaser. Many modern degreasers are water based and don't desolve crude as well as the old stuff did.
 

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Discussion Starter · #12 ·
So, are you using the brake cleaner in the spray can and emptying it into the tank?

I use it often on stuff, the non-chlorinated type, but only ever seen it in a spray can. Given how fast it evaporates I'd be wondering it it will loosen the crud then evaporate and leave the crud behind before I get it all out. :D

It would be a good way to get the moisture out fast though.

Well, got the solvent in there, giving it a good sloshing ever so often and let it sit over night... will hopefully get it drained out tomorrow and maybe try the muriatic acid approach to derust it.
 

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Discussion Starter · #13 ·
So, what's sludge supposed to look like?

I've been dumping this stuff out quite a bit... switched to a general solvent for de-greasing and such and poured out a tonne of this milky off-white stuff that seems to separate from the solvent. Also... when the petcock if removed, shouldn't the fluid drain out the hole? If I remove mine and shake the hell out of it, I might get a teaspoon worth at most.

This normal when cleaning a tank out? Water Sky Tints and shades Auto part Automotive window part
 

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Discussion Starter · #17 · (Edited)
Ya ... I was thinking that this wasn't quite right ... also, there is a lot of it it seems. I dumped last nights batch, added in about 1-2l more solvent today to slosh about and hopefully loosen more up.

Home Hardware sells Lye Crystals, which I guess is what I need. 500g or 3kg... is there a water/lye ratio? How about the muriatic acid option? Would that damage the plastic tube on the petcock and rubber on the cap?

I was looking at the Kreem liner kit, mostly because I've seen good reviews, and I can find it in Canada. Amazon.ca is no where near as good as Amazon.com :S
 

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1 can of Red Devil Lye per 4-5 gallons of water. I'm not sure what the ratio would be for the crystals. I'm also not sure about muriatic acid. I do know, however, that you should be extremely cautious with both muriatic acid and lye. Wear gloves and DON'T breathe in the fumes. Also, muriatic acid fumes will rust everything in sight, so try to work outdoors.
 

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. . . not sure about muriatic acid. I do know, however, that you should be extremely cautious with both muriatic acid and lye. Wear gloves and DON'T breathe in the fumes. Also, muriatic acid fumes will rust everything in sight, so try to work outdoors.
I've had very poor luck with muriatic acid. It reacted with the rust in my tank, but didn't dissolve it. The rust just puffed up into a thicker foam-like layer and stayed in there. In the end I broke it loose, little by little, tapping the tank with a mallet and blew the flakes out with an air hose. It took me all weekend to get the last of it out. Maybe there's a better technique to make muriatic acid work. If so, I'm eager to hear about it. But don't imagine it will just dissolve the rust away.

Phosphoric acid (30%), on the other hand, has worked for me. The liquid went in yellow and came out black. My rusty tank came out a lovely mottled grey color.. It was a different tank with a different degree of rust, so I may be comparing apples to oranges. But for what it's worth, that's been my experience.

As for Kreem, I've been told it's not compatible with modern gas, as it dissolves in ethanol. I can't vouch for this advice, but maybe another member has the straight word?
 

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Muriatic acid is good for cleaning cylinder walls and chrome plated items only.
Some straight kerosene might do the trick better, put some in and let is sit at least 24 hours minimum.
 
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