Gummed up gas tank

Hi All,

Restoring my my 82 seca xj650rj. It has been sitting for 22 years. Kids are grown and I want to go back to riding and loved that bike. I have the gas tank off and put vinegar in it to remove the rust but I have a lot of gum from the old gas that was left in it. How do I remove it? I gave up on the fuel petcock and just bought another one. It is like thick sludge

 

Hi Leora

I used the instructions here to clean one of my tanks, worth a read.

http://www.realclassic.co.uk/techfiles/petrol_tank_cleaning_and_rust_removal.html

 

Acetone and ATF ( the ATF is to keep rust at bay) and a handful of 3/8" nuts shake tank around a few times let it sit for about 15minutes and repeat several times , drain tank and use a magnetic extension and get the nuts out of the tank , see if tank looks better inside .

 

I just had my 280Z tank cleaned and all they did was put it in boiling water with sone strong detergent. Dish washing detergent would work. It removed all the gum. By the way, this works for barb also.

 

can of seafoam or berrymans carb cleaner

 

Good evening @Leora

Very good question - it depends on just how bad the tank is.

My example is:
-tank coating; This tank was coated with what looks to be POR15 - proper adhesion in some spots but not all
-scale rust
-varnish/gum
-it looked pretty bad inside

Removal process was something to the effect of:
1. Tank was drained of old fuel/varnish
2. Sun dried on concrete slab to evap most of the VOCs
3. Cleaned with 1:1 ratio of Simple Green + water three times
4. Rinsed thoroughly
5. Sun dried again
6. Tossed on kludge tank tumbler
7. Will know more when it’s done


Cheers,

 

Thanks for the reply. I have soaked it in vinegar 3 X now and that has removed a lot of varnish and what looks like thick blackish brown gunge. (varnish?) was wondering about putting parts cleaner in it and letting it soak. I cleaned the fuel petcock assembly which had the same stuff on it and the only thing that seems to remove the stuff is brake cleaner and I am not sure how much I would need. That stuff is pretty pricey for a tiny amount and mostly seems to be in a spray can. It is really hard to get all the liquid out of the tank so am reluctant to put anything in that could be a hazard to the engine later.

I bought a new petcock assembly and have replaced the brake master cylinder (sight glass was broken) and am thinking after sitting for 22 years it is going to need a carb rebuild. Was looking at a kit but not sure how hard it is to do. Messed with a bit of carb rebuilding years ago with my grandfather. Any thoughts on re chroming the carb covers?

 

You absolutely will need to remove and clean the carbs. Take them apart as much as you can and clean them with carb cleaner. Might then want to boil them for a few minutes and blow the out with an air hose. Mine didn’t need shaft o-rings but it hadn’t been sitting up.

Use whatever you want to clean out your tank. You can even boil with soapy water which will remove any varnish—just had my auto tank “boiled” out by the local radiator shop. When you finish rinse it out with plain water, then hook up a shop van in the blowing mode and stick the hose in the tank neck and leave it there until it is dry. On mine I sprayed the inside with some WD-40 just to give it a little coating until I put gas in it.

 

home depot has stuff called MEK , methyl ethyl ketone or something like that. it will take out all the varnish and most tank liners. it will also kill a few brain cells if you get a good whiff of it

 

very strong stuff will wash paint away as it drips on it