M-38 jeep YS carb

[1948willyman]

Just melted another diaphragm in the carburetor with ethanol gas. Will just pure gas help stop this or some sort of additive maybe cool the alcohol down?
Went through several of these over time and figure the fuel pump is next again
Anyone have ideas to help stop this? They say resistant to ethanol but must not be too much in my experience.

[wesk]

Run the bad ethanol gas 50/50 mix with non-ethanol off road vehicle gas. If you don’t have this option you can still mix 50/50 with aviation gas

[RonD2]

On-road non-ethanol corn-free gas is readily available at many gas station pumps in the Carolina's.
Cost is $1 to $1.50 a gallon more than corn gas, but it's worth it.

My local little airport has sold me a few gallons of 100LL (low-lead) aviation gas on occasion, but I found that corn-free is the way to go. It's all I use anymore.
And while the odds might be slim, if the man catches you with 100LL in your jeep (tell-tale blue dye) it'll cost you (and the airport) a pretty good fine.

Just a thought....are you using NOS diaphrams? Maybe age got them?

Good luck!

[wesk]

Your Carolina cops must be pretty bored to chase down Blue Dye Stains. I haven't seen or heard a case of any tank farm operator or off road gas user getting any punishment up here in Wisconsin in at least the last 30 years.

We had to be careful in the 60's when the USAF was still using avgas 115/145 in a few recips and all the piston powered ground power units since we used to take some once in awhile for our POV's and it had purple dye back then. AP's would lift hoods at the gate and lift air cleaners off to look for the tell tale purple stains.

[RonD2]

Your Carolina cops must be pretty bored to chase down Blue Dye Stains. I haven't seen or heard a case of any tank farm operator or off road gas user getting any punishment up here in Wisconsin in at least the last 30 years.

I don't know if they're too bored to chase gas bootleggers or not. My guess is they're probably plenty busy dodging bullets and out-of-control cars, but who knows?
Can't say I've ever heard of anybody getting ticketed for using avgas in a road vehicle, but last I checked it's still against the law --- so why give them a reason?

At my age I try to avoid trouble, especially the self-inflicted kind.
Have a Happy New Year Wes!

[Mike_B]

We can get Ethanol Free gas at a few local gas stations (Southern Maryland)...it's right at the island just like Diesel and 10% Ethanol, no mention of ON or OFF road use. I use it in everything except for my daily driver modern car.

Mike B

[4x4M38]

Same in Texas.

Just missing the lead for the valve seats.


And yes, ethanol free costs more, but remember, 10% ethanol gas loses about 10% in mileage due to the difference in Btu’s.

How using more gas to get the same distance saves the planet, but I don’t have the energy for those arguments any more.

[1948willyman]

Many thanks for the comments. All these came from kits purchased from various suppliers and stated to be resistant. None were NOS as Ron said. That being said, Will try as Wesk stated or just try 100% gas. If anyone else has an idea, Please comment on this . I guess trying to rig up a newer carb might help if it can be done but want to keep all original as possible.

[BB]

I would say you should look for ethanol free and don’t worry about the price.
Ethanol also is corrosive to the lining of your fuel tank, and you still have a problem with the fuel pump. Years ago when they started using ethanol we had a lot of problems with fuel tank senders failing also. Use ethanol free in your lawn and garden equipment to it cuts down on carb and fuel line problems.

[oilleaker1]

Up here, the pumps share three grades of gas with the same hose and pump. You get alcohol even if you dial up premium 91 alcohol free. Fiberglass motorcycle tanks begin to have their resin dissolve. That in turn fouls plugs and sticks the carburator throttle shafts etc. Very irritating. If you get desperate, you can make your own alcohol free gas by mixing one cup of water per gallon of gasahol and shaking the mixture for 30 seconds and let sit over night. You do it in a clear water plastic bottle so you can see the line between the two. Either siphon off the top or epoxy in a drain cock. The water settles to the bottom and takes the alcohol with it. This is ridiculous, but sometimes you have to get creative. E 85 gas is the worst crap I've ever run into. It separates and dissolves your brass pre-filter screen and turns it blue. It then coats everything with a thick brown sludge. Horrible stuff. Unfortunately this happened when a friend did me a favor a filled the tank back up for me after he drove my M38a1 with me on a run together. It sat all winter with that crap in a NOS fuel tank I was so proud of. I had to spend a day cleaning it all out, but I saved it. Oilly

[4x4M38]

Ethanol binds with water that is one reason its so bad.