# cleaning my gas tank???



## LMHmedchem (Feb 5, 2014)

Hello,

I am part way through replacing the carb on my Crafstman 536.881800 with the B&S PowerBuilt OHV 12E114 0268 E1 engine. When draining the gas this time I noticed some junk in the gas that looked like old leaves. I want to make sure that I get the gas tank completely cleaned out before running with the new carb or I will be right back where I started.

How should I go about doing that? My guess would be to spray in a bunch of carb cleaner and leave it for a while to dissolve any gummy sediment then clean with ammonia and then really hot water until all of the ammonia smell is gone. then leave it to air dry and finally rinse with some clean gas.

Is there a procedure for doing this? I can't understand why a machine like this doesn't have a fuel line filter.

Happy New Year everyone.

*LMHmedchem*


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## gsnod (Sep 2, 2013)

I've used ice cubes in the past to help clean tanks -- mainly metal tanks. Put the cubes in the tank and shake it around. After everything's melts, thoroughly drain and wash out. AND.....definately can't hurt to put a fuel filter in the gas line!


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## motorhead64 (Dec 15, 2013)

On plastic tanks I use hot soapy water, put cap on with duct tape on the outlet and shake. Drain out the cap hole and repeat. Rinse with hot water and air dry. Blow out with air compressor. Nice and clean. MH


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## YSHSfan (Jun 25, 2014)

gsnod said:


> definately can't hurt to put a fuel filter in the gas line!


Yes, it can hurt if the fuel system is only gravity fed, it can cut the fuel flow and make the engine run too lean and or stall.
Honda and Yamaha engines have just a screen as a filter to prevent this from happening.

If the fuel tank is located a few feet higher than the carburetor it may/will work or if the engine has a fuel pump it will definitely work with an in-line fuel filter.


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## Vermont007 (Mar 29, 2015)

I 've elected to install cheap (disposable) see-thru motorcycle fuel filters on all of my lawn and garden equipment . . . . including the Snowblower. They cost me something like 41¢ apiece when I buy a dozen or so on eBay.

I like them because they give me an insight into whether my fuel is flowing freely and when there is any debris accumulation behind the filter material.

At 41¢, I can afford to replace them once a year or as frequently as I see any obstruction . . . . and they even give me a little advance warning if I'm about to run out of fuel.


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## YSHSfan (Jun 25, 2014)

Vermont007 said:


> I 've elected to install cheap (disposable) see-thru motorcycle fuel filters on all of my lawn and garden equipment . . . . including the Snowblower. They cost me something like 41¢ apiece when I buy a dozen or so on eBay.
> 
> I like them because they give me an insight into whether my fuel is flowing freely and when there is any debris accumulation behind the filter material.
> 
> At 41¢, I can afford to replace them once a year or as frequently as I see any obstruction . . . . and they even give me a little advance warning if I'm about to run out of fuel.


Good to hear that those work for you.


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## cpchriste (Jan 19, 2014)

hsblowersfan said:


> Yes, it can hurt if the fuel system is only gravity fed, it can cut the fuel flow and make the engine run too lean and or stall.
> Honda and Yamaha engines have just a screen as a filter to prevent this from happening.
> 
> You may have put your finger on a long-standing problem for me. :banghead:
> Thank you.


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## YSHSfan (Jun 25, 2014)

cpchriste said:


> You may have put your finger on a long-standing problem for me. :banghead:
> Thank you.


Believe it or not there is another forum member with a Yamaha YS624 with steel fuel tank and no fuel pump that was having an issue with the engine running for a few minutes an shutting off.
Fast forward, he had installed a fuel filter under the fuel tank and with testing it was determined that the fuel filter was restricting the flow and making it starve.
He is waiting for snow to test it without the fuel filter and said he will make a video of it working as he loves the performance of the YS624 (we'll see how it goes).

I learned that on a gravity fed fuel system a conventional fuel filter can cause a restriction an make the engine run poorly/stall with the BMW Isetta guys where there is only a screen fitted as filter to prevent flow restrictions. 
There have been proven facts that the filter indeed causes the issue and a lot of the Isetta owners will warn you not to use a fuel filter.


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## LMHmedchem (Feb 5, 2014)

I cleaned out the tank as follows.
*
Wear eye protection when doing this, you don't want any of the solvents getting in your eyes. :icon_cussing_black:*

1. spray in a good amount of carb cleaner, at least enough to swish around some. Let that sit for several hours to dissolve any gummy deposits.

2. Rinse the tank a few times with paint thinner to remove anything dissolved by the carb cleaner. On the last rinse, allow the thinner to drain out the supply nipple to make sure that area is clear.

3. Add 1/2 cup straight ammonia to the tank, put on the cap and shake well. Be very careful to not get the ammonia on yourself from the supply nipple.

4. Fill the tank part way with very hot water, replace the cap and shake well. Drain the water and let some of it drain through the supply nipple. Repeat with the ammonia once and the rinse with hot water several times. You should not be able to smell the paint thinner or ammonia very much when you are done.

5. Despite the stupid design of these tanks, try to get as much of the water out of the tank as you can. Leave the tank to dry overnight.

6. If you do this in the summer, you can probably just leave the tank somewhere warm until it dries out completely. If you need to re-install it before it is dry, pour 3/4 of a dry gas into the wet tank and shake well. Drain as much of the dry gas out as you can through the supply nipple. It helps if you can let the tank sit for a while after this. Put the remaining 1/4 of the dry gas into the tank before you add the gas.

Thanks for the tips,

*LMHmedchem*


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## Vermont007 (Mar 29, 2015)

I'm not a chemical engineer but I need to ask if you're sure you're not producing a toxic vapor when mixing these other compounds with household ammonia . . . . which is poisonous in itself ?


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## LMHmedchem (Feb 5, 2014)

Vermont007 said:


> I'm not a chemical engineer but I need to ask if you're sure you're not producing a toxic vapor when mixing these other compounds with household ammonia . . . . which is poisonous in itself ?


It's a good question but no, there is nothing to be concerned about other than the normal precautions when using solvents. It is always better to do such things in a well ventilated area or outside. Some folks who use solvents allot, like in furniture refinishing, will use a respirator mask.

Ammonia has no reaction with the simple hydrocarbons in paint thinner or anything in the more complex mixture of carb cleaner. Ammonia is just a very good detergent, meaning that both grease and water are soluble in ammonia. The grease dissolves in the ammonia and then the ammonia/grease complex dissolves in the water and can be washed away. That's being a bit liberal with the chemistry that is actually going on, so the chemistry teachers my frown a bit, but it's close enough. All detergents work like this more or less.

You need to make sure that you never use ammonia in combination with any compound like bleach that may have chlorine in it, but other than that it's fine.

Anyone concerned with using ammonia could just any other strong degreasing detergent instead. The rest of the process would be the same. I like ammonia because it is very water soluble and so is easier to rinse thoroughly with minimal residue left behind.

*LMHmedchem*


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## Newt (Dec 27, 2016)

I use diesel fuel shake it up then dispose of it.


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