rust in gas tank

ben henderson /

I have a old tomos that will run but crap from inside the tank keeps clogging the carb enough so it won't idle on it's own

I have already tried evapo-rust...that left weird sheets on the lower inside/bottom that almost looked like peeling paint. I tried scrapping, and used a pressure washer.

Then I put in vinegar for 24 hours and cleaned as best I could.

Where there is bear metal it doesn't look bad. But there are still areas with the pealing paint stuff and there are larger particles now in the fuel filter and smaller stuff is causing it not to idle.

Did these tanks have some sort of lining that I ruined by using the evapo-rust?

Any ideas of what to do now?

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Re: rust in gas tank

someone probably did a Kream coat or something else, and did it shitty.

they were originally bare metal.

you wanna get all that nasty shit out.

then evaporust

then neutralize and fill with premix or coat with something quality. I like the por tank treatment. That shit is muy fuerte. como un toro.

Re: rust in gas tank

put somethig abraisive inside the tank and shake it up to knock everything off the inside walls. I use vinegar to remove rust but it has to sit for weeks to really be effective for that, and you have to neutrilize the acidic vinegar of it will flash rust.

Hopeflly you have read this:

https://www.mopedarmy.com/wiki/Removing_rust_from_a_gas_tank

Re: rust in gas tank

PEA GRAVEL , OR SMALL WASHERS AND NUTS , do the shake !

Re: rust in gas tank

just get a real deal pet cock they have a built in filter that slides up into the tank. it has three positions on off n reserve. get one w nipple straight down, then run an inline filter as well, clean carb again. dont forget to premix.

Re: rust in gas tank

ben henderson /

Im going to try it tomorrow...just need to buy some clean nuts.

I had read the post on rusty tank cleaning but nothing there mentioned the weird crap in my tank, but it makes sense if it was a previous attempt to seal the inside of the tanks.

Not sure if I can get a petcock/filter local but that is not a bad idea. The filter I have on it clearly only screens out larger bits.

Re: rust in gas tank

I made myself a gas tank cleaning kit. Find a bunch of SAE (nobody needs that shit) nuts or bolts. And count them. Throw them in the tank with bad gas. I keep my bad gas exactly for this reason. Or if it’s really bad go to Home Depot and get Muriatic Acid. It’s in the pools section, it’s cheap and lasts a long time. And will most def clean that tank. You want to cut it with some water though. Anyway fill it up. Throw the bolts in. Shake it around a bunch. And dump it out. Drain it. Count your bolts to make sure nothing is wedged in there and you got all of em. Flush it with bad gas. Then flush it with good gas, just enough to work. Then you should be good. If you’re worried about future rusting just make sure to keep the tank full if you’re storing it for a season. Honestly I almost always get away with just using bad gas and bolts. And not having to do the acid. Good luck Hope it works out.

Re: rust in gas tank

The tanks are not coated from the factory, they are bare metal. It sounds like someone previously coated the tank and the coating failed. The vinegar or evaporust won't touch the coated part. You can try shaking it with an abrasive like wood screws, gravel, etc or use some sort of solvent or both. Acetone might work.

Re: rust in gas tank

Moped Lar (OFMC) /

Just get another tank. They are a dime a dozen.

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