what have you used to clean up the fuel tank to the carb… especially after having ‘old’ gas sitting too long in the tank? i’ve tried sea foam, lucas injector cleaner, diesel fuel (10%), atf, techron, stabil and about everything that is reasonably priced… seems most are little better than none… but i’ve got some varnish that needs to be liquidated in my cars that sit too long with this modern overpriced gas. in short… looking for that Magic liquid that really works.
Since you already tried diesel fuel, you might try using 100% biodiesel instead of the type and amount you’ve been using already. That stuff cleans out everything (I’m told), to the point diesel fuel filters will need to be changed shortly after beginning to use it. just a idea. EDIT: I’m suggesting using 100% biodiesel in lieu of the 10% you posted as used already. John
What about using Sta-bil in cars that sit? It's supposed to prevent varnish. Never used it so can't have an opinion.
i’ve been using the stabil. but my main concern is cleaning up existing remaining varnish in a car tank-to-carb that the modern gasoline evaporated from. and i’m sure that there is some cheaper and better stuff than sta-bil.
I only run non ethanol in both of our hot rods. I use Stabil if a car will sit for an extended period.
I use Stabil in fuel that sits, like small engine fuel containers, don't know if it removes varnish though. I like MMO and use it in every tank of fuel in my heap. Don't know if it will remove varnish either but, it hasn't caused any...and I run the cheapest fuel I can find.
Has anyone ACTUALLY checked...to see if any actual cleaning was done ? Intake manifold ports "clean", cylinder head ports..."clean" ? Piston tops..."clean" ? When I was still working (retired), I drove a motorcycle 85ish miles back and forth in Los Angeles traffic to work every day. I noticed that the intake tract started getting a bit loaded up with garbage in a new bike. Carburetors need to come off to do a valve adjustment ! I found the Red Line cleaner worked VERY well. In one valve adjustment interval, the intake ports were back to a nice clean aluminum, the piston tops, clean. Yes, you can see the piston tops on many motorcycle engines with the carburetors / throttle bodies off. For some reason, the Red Line brand became all but impossible to find. I moved to the Lucas Cleaner. While the Lucas Cleaner does work, it takes almost twice as much as the Red Line to do the same job. It's been a long time back, but I did try a couple of others, stayed with the Lucas. Even into the fuel injected motorcycles, the throttle bodies still needed to be removed to adjust the valves. Same as the old days. The Lucas works well. Redline is better if you can find it. I put over 100,000 miles on four of my bikes and never had to clean or replace a fuel injector unit. Or...clean the carburetors on the older bikes. The Sta-Bil isn't really a "cleaner", and does not really work as one. MAYBE 1/4 the cleaning action as the Lucas. And yeah, I use it in my cars also. A tank full at every oil change. I just put a tank full into my non-HAMB car this afternoon. Never tried any home grown stuff. Mike
If the varnish you are dealing with hasn’t been touched by the aforementioned products, you might have to pull the tank and take it to a radiator shop that still “boils out” fuel tanks. As for the fuel lines, I would flush them using an aerosol carb cleaner, Gumout, B-12, etc. As a last resort, before the radiator shop, you might try lacquer thinner. Pour a quart in the tank and slosh it around and see how it works. Remove the sending unit and inspect. Good luck and let us know what happens.
If the varnish hasn't been touched by anything you've tried...it's probably not going to be touched by gasoline, either, and won't hurt anything if you just leave it there. As long as it's just a thin coat of varnish.
The best at-home way to remove varnish from a fuel tank is with lacquer thinner. If you can pull the sending unit and there aren't any baffles in the way wire a rag on a stick and get busy mopping. After all the gunk is gone take the fuel tank to a car wash and blast it out with soap and water, but if you want it really clean, take it to a radiator shop and have it boiled out. (While the tank is at the radiator shop, have a drain plug installed so you can drain the fuel out of the tank if the vehicle is going to be parked for an extended period) When it comes to trying to clean all the gunk out of fuel lines the best course of action is replacement.
I haven't bought it in a while but a couple of gallons of carb cleaner that you soak carbs when you rebuild them would remove varnish. You would need to pull the tank and put a gallon or two in and then roll the tank to let all surfaces soak. Then pour the carb cleaner back out and then power wash the inside of the tank. That's how I would approach removing varnish.
Alcohol. Either 99% isopropyl or E85 fuel. I made this conclusion when cleaning out gummy crud left in the bottom of a five gallon pail of old, rancid gasoline that I had left to settle. Obviously if the gum separated from gasoline, gasoline was not going to re-dissolve it. So I tried some alcohol, and it dissolved it lickedy-split. So whenever I have trouble due to suspected gums or varnish in cars that have really old gas in them, I add a gallon of the isopropyl alcohol or several gallons of E85 fuel. The E85 fuel has the advantage of being cheaper than real gasoline here. And yes, I agree that E85 creates lots of problems when used in old cars that aren't driven often. However, it certainly can be beneficial when used for a specific purpose.
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