Shopping list:
(*) Phosphoric Prep & Etch by Klean-Strip (Homedepot $15.00)
(*) Handful of bolts, nuts, BB's or similiar metal objects
(*) Telescoping pen magnet
(*) heat gun or hair dryer
(*) 1-7 days without a gas tank
Here's my gas tank before the treatment
![Image](http://i78.photobucket.com/albums/j109/megaloxana/FZR%20how-to/Rusty%20YZF%20Tank%20How-to/RustyYZFtank2.jpg)
![Image](http://i78.photobucket.com/albums/j109/megaloxana/FZR%20how-to/Rusty%20YZF%20Tank%20How-to/RustyYZFtank1.jpg)
FIRST...REMOVE THE PETCOCK and ANY SENSORS Plug up the holes and make them water tight. I cleaned the area well and used duct tape, but it did not hold over night and leaked. I would recommend using some some plastic or sheetmetal, drilling holes to match the petcock and bolting it to the gas tank. Place some duct tape between your blockoff plates to form a gasket.
Now you want to do is get rid of the loose rust. Do this by dumping in some handfuls of bolts, nuts, even metal BB's. I bought a 50/pack of mahine screws & nuts. It's good to know the number of objects you're putting in so you know if you got them all out.
![Image](http://i78.photobucket.com/albums/j109/megaloxana/FZR%20how-to/Rusty%20YZF%20Tank%20How-to/Bolts.jpg)
Now you want to shake them around in the gas tank. You want to use a motion so that the nuts&bolts slide across the surfaces of the gas tank(think sandpaper motion). Do this til your arms get tired, take a rest, then do it some more. Get a flashlight and take a look inside, make sure you got all the big flakes. If you're done, then fish out all the bolts&nuts with your pen magnet.
Wash out the gas tank with water
Next pour in the Prep&Etch, I initially poured the whole thing in but 3/4 of it leaked out overnight. I went ahead and used the 1/4 that I had left and got excellent results, I just had to turn the gas tank around a lot more. Shake the gas tank around every few hours or so and sit it down on a different position everytime. If you have light rust, then 24 hours might have taken care of the rust. My results were after 3 days.
![Image](http://i78.photobucket.com/albums/j109/megaloxana/FZR%20how-to/Rusty%20YZF%20Tank%20How-to/PhosphoricPrepEtch.jpg)
After you are satisfied with the results, dump the liquid out of your tank. Now thoroughly wash out the inside of the tank with some soap and water. Then use a hair dryer or heatgun to completely dry out the inside of the tank. Refill with petrol of your choice.
![Image](http://i78.photobucket.com/albums/j109/megaloxana/FZR%20how-to/Rusty%20YZF%20Tank%20How-to/YZFGastankdrying.jpg)
..AND the results..
![Image](http://i78.photobucket.com/albums/j109/megaloxana/FZR%20how-to/Rusty%20YZF%20Tank%20How-to/RustFreeYZFtank-1.jpg)
![Image](http://i78.photobucket.com/albums/j109/megaloxana/FZR%20how-to/Rusty%20YZF%20Tank%20How-to/RustFreeYZFtank3-1.jpg)