I made the mistake of trying to start a 82RX7 that has been sitting for years. For that mistake I had to rebuild the carb. I just dropped the gas tank to clean. I found sludge from the old gas. How do I get rid of the sludge?

 

What's worked for cleaning the tank my FD:
1) Wash the tank thoroughly with simple green and water. Use a brush if necessary. If simple green won't cut it, perhaps you need to dump in naptha or something really punchy, then wash with simple green.
2) Rinse the tank thoroughly. Set it upside-down to drain.
3) With the tank upside-down and suspended, point a hot air gun into an opening and force-dry it. Mine dried in a few hours like this.

Dave

 

I had the same problem.
Here's what I did.

1. Drop the tank (is a pain in the butt since the strap bolts are like 4 inches long and have fine threads)
2. Empty any pre-existing gas.
3. Pour a whole bottle of CLR in there (comes in a gray bottle) along with a gallon or two of fresh gas.
4. Swash around the CLR and gas mixture for a while.
5. Dump into bucket or something responsible (**cough**stupid neighbor's lawn **cough**)
6. Repeat once or twice to make sure you got a good bit of the sludge and rust out.
7. I then let it sit for a day or two for anything else to evaporate.
8. Re-install tank and new fuel filter.

I'd say change out the fuel filter every 1000 miles for the first 3 or 4000 miles just to make sure you get all the CLR out of the tank.

http://www.scottslair.com/Archive-Fi...tanksludge.JPG

That's a link to a pic I took of what came out of my tank. The clear layer is gas; the stuff under that is the sludge and rust.

 

Thanks for the advice. I went with the simple green since I already had a bottle. It seems to have worked. I reinstalled the tank, flushed the line and installed a new filter.

My new problem is that when I turn on the fuel pump the carb literally fills with gas. My inclination is that I need to pull the carb and check to see if I forgot the gasket to the needle and valve assemblies.

Any other ideas of what might be the problem is appreciated.

 

-.- dont use simple green it is bad for the engine... at least for toyotas i dont know about mazdas

 

I did say I rinsed it out thoroughly.

Simple green attacks aluminum. It makes the outside of aluminum engine parts look ugly. I don't think tiny residues of the stuff mixed with gasoline and burned in the combustion chamber will make a darn bit of difference.

Dave

 

You'll also find people referencing taking the tank to a radiator shop to get boiled out.

 

Has anyone heard of having the tank re-coated inside (after cleaning of course) to keep any rust from falling into the tank and mixing with the fuel? I wonder if its worth this step. While we are on the subject, Does anyone know a place to have the fuel sending unit rebuild or replaced? Might as well do it well the tank is down.

 

yes its worth it

 

Sorry I don't mean to hijack the thread but does anyone know where I can get the fuel sending unit replaced or rebuild? Preferably somewhere in Southern California.