Topic: So you wonder what ethanol does to your fuel system?

[Rickf1985]

Here is a quadrajet I had on the shelf for about a year that I was going to rebuild for my Winnebago. I apparently forgot to drain the gas out of it and this is what ethanol in the gas will do to your fuel system when it sits. I yearn for the days when it just turned green and fuzzy!

[tmsnyder]

Terrible stuff. I've replaced or rebuilt at least 5 small engine carb's around my house because of that garbage.


I have a Sunoco about a 1/2 mile from me where I fill up with ethanol-free before parking it at the end of every trip.  I try to arrive at the gas station as close to empty as possible, that usually means putting just what is needed into the tank while on the road home to just get me to the station.


It's significantly more money, around 20% more, but if it prevents problems it's worth it.

[TerryH]

I have a portable Honda generator for my RV and a portable Champion (actually works well) mounted on the tongue of my workshop cargo trailer. I've only ever used ethanol free gas in them and no fuel related problems with either to date.
Doesn't take long for those small carbs to foul.

[Rickf1985]

In the North East it is next to impossible to find ethanol free gas, In NJ it IS impossible to find.

[87Itasca]

Long story short, I haven't started mine in a good three months, and the gas in there is between 8-12 months old. Not looking forward to trying to start it. Need to run it out of there somehow. Guess I should buy a transfer pump.

[Rickf1985]

You could jumper the wires at the safety switch by the oil pressure sensor, then unplug the power plug on your distributor so you are not running power to the ignition module. Disconnect the fuel line at the filter under the RV at the step and run a line from there to a container and lastly turn the key on. This should run the electric pump in the tank. Depending on how much is in there you are going to want to have substantial storage! 55 gallon drums come to mind and then remember you are storing large amounts of a hazardous substance illegally. I would pump out ten gallons and then hook the lines back up and see how it runs on what comes through. The initial ten gallons will have any separated alcohol so that will be out of the system safely. If it runs alright then just run it till the tank is low and fill it up. Saves you from storing all that gas. Then take the first five gallon can and set it aside and the second one start using in your lawn mower, only put in roughly what you will use each time you mow so it is not sitting in the mower. This is called waste not, want not.

[87Itasca]

Is the filter by the power side door step, or the drivers cab step? I'v never seen it, and I am sure it is seriously in need of changing.


Along with flushing the brake fluid, but that's a project for another day. 

[BrandonMc]

wow, bummer. How'd it all clean up in the end?

[tmsnyder]

In your basement storage area, on the frame, ~4' behind the front passenger side tire.  Look for an access panel screwed onto the back of the storage area, mine was wrapped in the liner material, like thin carpet.  Take off the little panel and the filter will be right there on the frame.  At least on mine, different manufacturer but same chassis.  Filter should be in the same spot.

[Rickf1985]

He has a Winnebago, it will be in the line on the inside of the frame somewhere in the vicinity of the side entry step, passenger side. It may not be there, someone had taken mine out and just put in a piece of fuel line. I did replace the filter, that little filter in the carburetor is worthless!

[Rickf1985]

wow, bummer. How'd it all clean up in the end?

If you are talking about my carb I did not get into cleaning it yet, I pulled another one off the shelf.

[Oz]

Excellent write-up!   

[Schmitti]

In Europe, the proportion of methanol in gasoline is a major problem in all classic cars . What works with metal parts in the gasoline system just like that is a huge problem with the old rubber pipes and especially with the aluminum parts of a carburettor . We also have only little help here. We change from gasoline with ROZ 91 (10% alcohol) to more expensive gasoline with ROZ 95 (5% alcohol) or even higher quality grades. But it does not help really well, because the only chance is to consume a lot of driving / gasoline. Standing vehicles also mean longer service life and thus exposure times of the gasoline / alcohol. Without a catalyst it helps to use a lead additive from time to time. As a precaution, ALL rubber parts of the fuel lines should still be replaced. After every metal in the pipe, a filter should be used in the vintage cars to stop any flakes that clog the carburetor nozzles. Carburetor & Co can only work properly with ultrasonic cleaning.
Great misery.
Greetings from GermanyThomas

[tmsnyder]

It's worthless if something manages to get through to it, it plugs right away and protects the carb.  It's just a last line of defense, but some people might be struggling with fuel delivery problems and not realize that there's a tiny, cheap little filter at the inlet of the quadrajet that can be plugged up!  I just wanted to put that out there in case people didn't know it existed.

He has a Winnebago, it will be in the line on the inside of the frame somewhere in the vicinity of the side entry step, passenger side. It may not be there, someone had taken mine out and just put in a piece of fuel line. I did replace the filter, that little filter in the carburetor is worthless!

[Rickf1985]

In Europe, the proportion of methanol in gasoline is a major problem in all classic cars . What works with metal parts in the gasoline system just like that is a huge problem with the old rubber pipes and especially with the aluminum parts of a carburettor . We also have only little help here. We change from gasoline with ROZ 91 (10% alcohol) to more expensive gasoline with ROZ 95 (5% alcohol) or even higher quality grades. But it does not help really well, because the only chance is to consume a lot of driving / gasoline. Standing vehicles also mean longer service life and thus exposure times of the gasoline / alcohol. Without a catalyst it helps to use a lead additive from time to time. As a precaution, ALL rubber parts of the fuel lines should still be replaced. After every metal in the pipe, a filter should be used in the vintage cars to stop any flakes that clog the carburetor nozzles. Carburetor & Co can only work properly with ultrasonic cleaning.
Great misery.
Greetings from GermanyThomas

Thomas. You mention Methanol, Is that the alcohol that is used in Europe? Over here we use Ethanol which is less corrosive than Methanol. Methanol is still used for racing but most of the parts involved in the fuel systems on the race car are set up for the Methanol. Stainless steel is used extensively in most newer fuel systems and in the race cars.

[Schmitti]

Sorry, I did not pay attention to what Google translated . We also use Ethanol from "organic" (rapeseed) production instead of Methanol.
Thomas

[fasteddie313]

Ethanol absorbs water like brake fluid does.. Water rusts stuff..


Gasoline don't mix with water too good.. Floats on top right?


Ethanol mixes well with water, makes nice vodka right?


that's the main problem..
You can help this by not exposing your fuel system to air the same way that you don't expose your brake fluid to air..
I don't really know exactly how the tank vent plumbing is done on the old MH, but tank vents to atmosphere are a no no with ethanol..
It will suck all the humidity out of the air and place it in your gas tank and then in your carb..


prolly absorbs out of the air right in your carb real good too.