Vintage Dirt Bike Q & A

I am cleaning my tank which is filled with gunk of all kinds and I know some nasty acid is an option, but I don't want a Hazmat team at my house. Is there any relatively safe chemical cleaners to eat that crap out of there?

Most people tell me to get a new tank, but the paint is nice and original with no dents.

Sorry, I don't know of a special cleaning chemical for gas tanks, and I've never coated or 'creamed' a tank (although I should have). Here's what I did, and the results...

My MR tank was really rusty inside, with heavy brown varnish deposits in the petcock area. I used acetone to loosen the varnish, and scraped the parts I could reach by hand with a long flat rod. I read later about someone using gravel, which I think is a great idea (I'd think small, sharp-edged gravel might be best).

At this point I should have coated the tank, but instead I reinstalled it on the bike. So much stuff had been loosened by the cleaning that the petcock inlet 'snorkels' were clogging up; the in-line fuel filter I put in looked like new, but no gas flowed. After many hours of work, I was able to get a free-flowing petcock despite a fuel tank full of floating debris (I pulled the tank off many times and flushed it out with gas, the crap came right back). Then my petcock began to leak and my patience ran out, and I bought a new Clarke tank.

I would suggest cleaning the tank well, then applying a fuel-tank liner coating (http://www.motorcycle-superstore.com/1/ ... &zmap=7407, http://www.kbs-coatings.com, etc.). If you need a gasoline-PROOF sealant, I highly recommend Gasoila E-Seal (http://www.gasoila.com/products/items/eseal.html).

You don't have to buy a new tank, but you may not be happy with the results of cleaning alone.

Ray

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'74 CR125M (175cc), '75 MR175, '82 RM250Z, '08 YZ250F, '14 Zero FX electric, '14 Zero MX electric, '18 Alta MXR electric

I used a combonation of radiator super flush, small wir brushes,1/4 nuts and WD40. Turned out pretty nice. did have to disposse of the radiator flush at the local oil change place.

Thanks for the help! I'll see what I come up with. I like the gravel concept.

I removed the entire fuel filter bowl from tank and have been flushing, but the gravel might help loosen up the big crusted debri.

I cleaned out my rusty steel CR125 tank by filling it with a weak solution of phosphoric acid (must be phosphoric, no other type!) and water with a handfull of drywall screws. I securely covered the filler hole and petcock hole then wrapped the tank with old towels and 3 layers of plastic bags.
When my wife was out for a few hours I put it in the clothes dryer (no heat) and packed it with more towels to hold it firmly in place so it wouldn't bang around. I spun it in the dryer for two hours. It loosened all the rust and scale beautifully.
I bought a tank sealer kit POR-15. Don't use "creem" kit. Follow the directions to the letter. I dryed out my tank by directing a hair dryer airflow with a hose into the tank a on medium heat for 24 hours. The tank must be completely dry for the sealer to work.
My tank turned out great.

You can do a pretty good job by picking up one of those quarts of BB's at Wal Mart and putting them in there and SHAKE SHAKE SHAKE - SHAKE SHAKE SHAKE - SHAKE YOUR BOOTY!

I'd suggest looking around for a non-flammable cleaner that you can "pour" into the tank with the BB's. Not much but enough to wash away anything the BB's break loose or break off in there... Mineral Spirits would be my personal choice or even Vinegar which is about 6-7% acid and works wonders if left overnight etc...

Mike

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The Race Isn't Over Until YOU Cross The Finish Line!

I bought a '77 MR250 many years ago that had old gas in the tank (very stinky) and it had a lot of condensation rust on the upper part of the inside of the tank. I used the small sharp gravel idea by dropping in a small handful of gravel and putting in about a pint of gas then put the gas cap back on and plugged the vent tube on the cap and shook it around for about 20 minutes and it seemed to do a pretty fair job of cleaning it up.

If you want to get fancy, you can always fill with water/washing-soda solution. Attach one lead of batter charger to a bare metal part of the gas tank. Take the other lead and attach to a small clean piece of iron or steel and suspend it in the solution in the tank. It's a bit of a chore to get it suspended where it is just in the liquid and not touching the inside of the tank. Turn it on overnight and most rust should dissappear. Having said this, it is a heck of a lot easier to fill the tank with pea gravel, or some other type of abrasive, pour in some liquid (WD-40 works well--but you have to buy the Big Boy container, not a spray can) and shake the heck out of it. Rinse, repeat a couple of times and results are usually pretty good and you don't risk blowing up a battery charger or your garage. Careful of using acetone, you can ruin the paint on your tank if it gets on the outside and isn't removed promptly.

i like the dryer one, but use a sleeping bag and some bud lite. wrap the tank in the sleeping bag put it in the dryer then have a couple of buds and the tanks clean

Evapo Rust is the rust removal product you want. It doesn't burn, the label says it is drain disposal legal in most places, and I'll be darned if it doesn't remove rust just as well as the acid products. The label goes all technical about how, so look that up if you want. $20 for a gallon of relatively safe rust remover is a good thing.