Yellowed Gas Tank

Does anyone have any tricks on how to restore plastic gas tanks. I know it is best to not store fuel in it, but once its yellow or turning yellow, can you get it white again?

there s a place in the U.K. saw their add in VMX

The answer is no. Both four stroke and two stroke tanks stain due to the fuel and the Acerbis plastic reacting together. Draining the fuel after every weekend of riding will help prevent staining of a good tank.

If the staining is not too bad you can sometimes get a nice cream colour by scrapping the surface of the tank with a sharp blade to remove worst of it and then sanding and polishing starting with 280 grit and working down to 1200. Use wet sanding lubricated with water and weak dish wash liquid mixture. Final polish with Jiff or similar household mild abrasive surface cleaner and polisher to get a shine.

There was a good article on the process in a VMX magazine a couple of years ago. I can find it if you want and post.

I have tried chemical bleach and peroxide treatments to no avail. The best approach (other than looking for a nice white tank) is to get it as good as possible and then covering the tank with a full coverage set of perforated decals from MXM or make them yourself. Use paper to make a template that folds around the tank covering the surfaces you want hidden by the decal. Then when happy with the template transfer the shape to a sheet of white perforated decal. Decal suppliers should sell you suitable sized sheets of decal material.

If you want you can ditch the white tank for an aftermarket tank. Clarke make a nice tank that suits 83 models and 84 models. 84 needs slight seat foam mod and right side panel needs trimming. Also works on 85 four stroke and auto.

Good luck.

yea that was a lot more helpful isn't there a sealer and paint deal to fix for that to?

I got the darker than down to a lighter beige with polishing.
I may try painting it next. I painted older faded plastics with rustoleum gloss white paint before. It held up if nothing scratched it. The preparation is the key. The more we prep it the better it will look. In the old days the gas never effected the paint. I'm not sure about this newer blend of gas. We do need to let the paint harden/cure for a while.

I have no experience with painting tanks so bow to others experience. If you want a garage queen then by all means paint it and never use fuel in the tank. If you want to ride and race then use the decals. It looks quite good in my opinion. In the mean time keep your eye open for a tank in better condition than yours and swoop on it. What year is your bike?

I painted my old tank, the paint stuck for a few weeks.
What happen was bubbles started to form here and there.
Then i found a better one for 35 bucks on ebay, i wasted way too much time sanding painting blah blah.
Down low its a bit yellow, i can live with it.

the 400 looks ready for action!

What paint did you use? Could be the gas vapors coming through the plastic?

Enamel? Water base? Oil based paint?

It was the gas vapours, tried a few kinds of paint.
The tanks plastic needs to sweat and breathe, why they offer perforated tank decals now.
The paint will rub off in some spots after a few long rides any ways.

Rebuilt shock and lube the bearings in the S/A.
Had a good test/first ride for the season, hit some snow and ice here and there but was fun.


View: https://www.youtube.com/watch?v=VgtQz_wOWuM

I might end up polishing it till it's the light beige and live with it.

Your bike sounds good the mud was loading the engine. I like how the whiskies sound.

Thanks for all the tips. I went after it like a tweeker using Soft Scrub, it took a lot of the yellow away. Still a little beige on the bottom. It's a 1985 500XC by the way. I'd like to make one out of aluminum and powder coat it.

86 400 ccw,

Be aware of the springtime bear wake up. I burp the bike more often. The pines drowned out some of the noise. I had a bear stand up 10 yards off the trail as I flew by once. I'm very careful now. I make a lot of noise in the pines.

On your swing arm where your brake cable has that connection on it. It's wearing the corner of your swing arm. Put a piece of shrink boot over it and shrink it over the connection.

that would be very very sweet.

Oh yah seen bears before, the wild horses are the coolest thing for me.Seen it all pretty much. Almost had a head on with a moose doing single track.
On my brake cable i have some duct tape in the that 1 spot, easy to change.

My son and his girl friend was riding a head of me along side a river. A foot off the trail was a coiled up snake. They didn't see it but I did. They were shocked.

I had a Beagle bite my leg once like a cartoon he was horizontal above my work boots. I was on the road at a stop sign. Then I dumped the clutch as he chased me across the on coming traffic. Another time I put the front wheel up as he charged me. He stopped.
The pop of the pipe sets off something in there ears. I found that out when a pit bull was charging me and i shut the bike quickly he stopped. Remember this tip.

That '86 400 wxc is one awesome bike.

Ok I started buffing my plastic gas tank with a car polisher using the dupont white compound. Some of it is a off white while the rest of is a darker than color. I need the heavy duty dupont red compound next. It I can get the tank to the off white color then polish it up with a cleaner wax to a shine it will be ok.

The color is from the inside out. The entire thickness is that color. You will sand thru before you get rid of it. There is a reason you have been told paint is the answer, and seal the inside of the tank first. Caswell is the best for that as it will not dissolve from the alcohol in our fuel supply where Kreme and POR-15 will dissolve because they depend on solvent evaporation to cure. Caswell is an epoxy