Hi All, what is the best thing to clean out a chainsaw gas tank?

 

Depends on why it needs cleaning. I've used vinegar and baking soda on gummed up metal tanks, not sure if that mixture is ok on a plastic tank.

 

Small gravel and water in tank with a vigorous shaking. Follow with a carb/choke cleaner shaking rinse and blow dry with compressed air.

Works for me.

RR

 

Sand and water, both of which are the last things you would want in the carb, and would destroy an engine, Hmm.
How bad is it?
Just need rinsing out, or been years with old gas in it?

 

How are sand and water going to destroy the engine when you use it to clean a gas tank? I've seen lots of gas tanks with a lot of water in them and it didn't ruin the engine. How is sand going to go through the carburetor and into the engine? I have used water to rinse tanks multiple times, rocks, ball bearings, whatever it takes to knock the rust loose and scratch around and clean the tank. As long as it gets rinsed and dried thoroughly, it's not a problem.

 

As Cheese said - water in the tank isn't a big deal. Long ago I brazed up a couple of motorcycle gas tanks, the first thing I did was remove the gas and replace it with water. I've cleaned several old automotive gas tanks that were gummed up with gas that had turned to 'varnish' After the cleaner was well rinsed with water and then drained a final rinse with a solvent normally removes the raining water. Using water in the cleaning process has never presented an issue with engine.

 

Many years ago my dad was brazing the gas tank off our hay baler, he rinsed the tank with water but didn't leave the water in the tank, it blew up and he got terrible burns. Moral of story: If you are going to weld a gas tank leave the water in the tank. Have a good one. Geo

 

Dulley noted Geo.
It doesn't seem like old gas was left in there,it's more like black gum or sealant, no rust.

 

If it's just gummed up from old gas any of the cleaning methods mentioned should work. Sealer can be difficult. I've had issues with sealer peeling on my tractor tank since I've had. I believe the last time I cleaned it I got about 95% removed and don't expect any more problems. 20 yrs ago I removed all that was loose but over the years more started flaking off

 

Is it a metal tank and can you remove it? I just cleaned out a badly rusted gas tank on a 1973 Briggs and Stratton 5 hp. I removed the tank and put small rocks in it with some vinegar. Shake it for about 15 minutes. That got out all the big flakes of rust. Then I got some muriatic acid from home depot and filled the tank with that for about 10 minutes. That turned the inside of the tank silver again. Then I rinsed it with vinegar and baking soda, then with water, then with gasoline. This might work to remove gum and sealant. I also read on a motorcycle site that its not a good idea to seal a tank because of pealing.