MOPED ARMY

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

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.

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.

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