1300 sputters after partial fill up

[TequilaSunSet]

I'm here in the Philippines, driving my 75 Brazil 1300 for the first time (bought in April and had it driven in May to the island) and added 5 liters cuz fuel guage is not working. As soon as I drove away from fuel station started sputter under power. I could push the clutch in and rev it no problem, limped it home.

So do I need to drain the fuel tank, or is there an additive I can add? I'm gonna replace fuel filter just cuz. Previous owner used only shell gas, I used some name i never heard of.
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Don't harsh my mellow...
1985 Hightower Vanagon 1.8T- Gone
1972 Panel Bus- Gone
1967 Bug- Gone
1964 Euro Sunroof Bug- Gone
1969/72/63 Sunroof Bug- Gone
1975 Brazilian Bug in the Philippines 🇵🇭- New to me

[Eric&Barb]

Try draining the carb into a small glass jar and see if there is water contamination.
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In Stereo, Where Available!

[TequilaSunSet]

[Eric&Barb]

[glutamodo]

In my experience, the only time I had an INSTANT change in how the car ran after filling up with fuel was due to vapor lock, which happens from the heat of the engine "soaking"into the fuel pump while it's shut off at the gas station. The fuel itself is going to be the same right off the bat when you start up, you have the fuel in the carb, the fuel pump and the line from the tank, so you should not notice an instant change in running.

But heat-soak-vapor lock, that became so predictable for me in my 62 Beetle, that I would intentionally leave gas stations onto side roads or other parking lots expecting the engine to die. Sometimes I could overcome it by going hog-wild pumping the gas pedal trying to get whatever I could out of the accelerator pump. If that failed, I would game the system, I would open the hood, pull the vent line from the tank, blow into it, plug it off with a golf tee or other such and with the tank pressurized it would break the vapor lock. Then remove that from the vent hose and go on my way. The fuel pump generally stays cool enough to avoid vapor lock, from the fuel flowing through it at most times.

Having said that I have had a couple of instances of contaminated fuel over the years. Both times, I mostly noticed it as how the engine sounded while I was driving on the highway. I noticed a shift in power and knocking, and I think both times there must have been diesel mixed in with the gasoline, because both times the problem went away after I refilled the tank. But I did not notice the difference "instantly" after fueling up.

Oh wait a minute... when I hear of Brazil cars, I have to wonder if you have an engine designed for high-alcohol fuel. Or "ALCOOL"
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Andy T.

"What is Glutamodo, Horror of Toyko, besides total, fiendish, quality-a-you brain!"

[Dusty1]

Favorite rat rod fuel hack:

If you ride around with a bunch of crap on the roof rack anyway, add a motorcycle tank to the pile. I have an old King Sportster tank that sees use all the time as a bypass tank for vehicles with stale gas.

Spare tank can be used gravity fed straight to the carb bypassing the fuel pump or gravity fed to the fuel pump.

[TequilaSunSet]