Dirty Johnson Gas Tank

[L8teron]

I have a 1949-56 Johnson model HD25 (2.5HP) that has been sitting for 20+ years with gas in the tank. The gas cap had broken so the gas had been able to "harden" on the botton. I have tried soaking in solvent and also put in nuts to shake around and try to break it up. I am barily getting anything out of the tank. Can you take these tanks apart to clean and be able to seal them back? It looks like it will come apart?
Or do I need to find a new tank?

 

[F_R]

Re: Dirty Johnson Gas Tank

There are many solvents that work to some degree, and some that don't work at all. The cheapest and safest is plain old rubbing alcohol from the grocery store, and it works. Use that with your nuts and bolts and shake till your arms fall off, then rest and do it some more.

 

[Silvertip]

Re: Dirty Johnson Gas Tank

Remember, shaking bolts around inside a metal gas tank that contains flammable liquids could explode from a small spark. I'd be extremely careful using that technique. Unfortunately, there aren't many options that are any safer.

 

[bogggar1]

Re: Dirty Johnson Gas Tank

Look around I found 3 six gallon gas tanks at a yard sale... One was good, one had a stuck gas float, the last was junk so I took out that gas float and had 2 good tanks!!! $5 a piece wasn't too bad because I sold one for $10 and scraped the junk one. Or just spend the money and buy a good plastic tank of the fuel capasity u require and be done with it!!!

 

[CATransplant]

Re: Dirty Johnson Gas Tank

I assume you have the tank removed from the engine. One thing that will work, pretty surely is carburetor cleaner...the type that comes in a gallon can with a basket...

Most of the residue will be on the bottom of the tank or pooled up in one area or another. Fill the tank with enough carb cleaner to cover the buildup and then some. About half full is plenty.

You dont need any nuts or marbles or anything else...just time. Open the tank vent, and put the thing somewhere warm and let it sit for several days. Every once in a while pick it up and give it a good swish around to redistribute the cleaner.

Keep checking in the tank until you see the crud is dissolved, then dispose of the carb cleaner in a safe way. Follow up by rinsing the tank, first with water...several times, then with alcohol or shellac thinner, which is the same thing, only cheaper. After you empty the alcohol out, put the tank in the sun with the cap off and wait for it to evaporate completely. Once the alcohol is all gone, put some premix in the tank and swish it around to coat the inside with the oil in the premix.That will prevent rusting.

You'll be surprised at how well this will clean things up. It may take a few days, but it'll do the job.

One caution: You're going to spill some of the carb cleaner on the paint, which will damage it. No matter how careful you are, that'll happen.

 

[L8teron]

Re: Dirty Johnson Gas Tank

Thank you gentlemen, I will give this a try.

Appreciate your help!!

 

[samo_ott]

Re: Dirty Johnson Gas Tank

L8, the HD25 was made from '46-'50. Then in '51 it was the HD-26 and then in '52 they started the many year run of the famous 3hp JW-10. I actually have 3 of the HD-25's but have never tried to get any running... I'll try in time!. I like the method of cleaning the tank though. Carb Cleaner, not cheap though.

Let me know if you get it running and what parts you needed/found

 

[samo_ott]

Re: Dirty Johnson Gas Tank

Oh, and BTW, to answer your original question, yes the tank can be opened up and cleaned/repaired but it's got to be cut open and then must be re welded together. Standard practice for antiques where there's no replacement parts anywhere. I'd try and clean it first.

 

[reload]

Re: Dirty Johnson Gas Tank

There is a product called Metafin (SP) from the Magnus Corp that works well if you can find it. I think it comes in a aresol as well as a squirt can.