I'm stuck...really stuck.

[Nesse1]

Use a torch, or at least a hot air gun. If there is enough nub sticking up, cut a slot in it with a dremel cut off disc. Cutting down into the carb body a little typically isn't a big issue either. Worst case, drill a hole in the nub and then pound in a torx bit. That's safer than using an ezout, which love to break off.

 

[projectnut]

Another product you might want to consider is PB Blaster. I've used it on a number of stuck and corroded fasteners, and it's always worked. Like your previous solution I would let it soak for at least a day. I would use it in a place with good ventilation. It really stinks.

 

[FOMOGO]

In the distant past I recall drilling into the area behind the screw, or removing a plug (don't have one handy to look at) and blowing the offending piece out with compressed air. Mike

 

[cross thread]

Concentrated heat ? Soldering gun .

 

[Cadillac]

Heat it up and I’d use a tight spiral e-z-out. PB blaster when the part is hot it will wick right in.
Might be time for a “g” series.

 

[brino]

Is the carb off the bike?

If so, you might try an ultrasonic cleaner.
Fill the tank with plain old water, put the carb in a zip-lock bag (or two) filled with your solvent/lubricant of choice and put the bag in the water.
Give it a few hours to "vibrate".
(freezer bags are a little tougher)

Brian

 

[mickri]

Another thing that helps sometimes is tapping the end of the screw with a hammer. Lots of light fast taps will sometimes break the corrosion.

 

[SLK001]

I've had good luck using vinegar to dissolve old gasoline deposits - especially the gas with ethanol, so +1 on that.

 

[RJSakowski]

All the recipes for penetrating oils are intended for steel or cast iron. They work by having a low enough viscosity to work into crevices to help by busting up the rust up the rust and providing some lubrication. Brass in aluminum is an entirely different animal. The fastener is stuck because the aluminum oxidized due to moisture ingress around the thread. Aluminum oxide is about 50% greater in volume than the aluminum so the fastener became tightly wedged in the hole.

The best method of attack would be to use something would dissolve the aluminum oxide. Chemically, the aluminum oxide is essentially the same as an anodizing coat. The problem is that the most effective solvents also attack the base metal. I have encountered this problem removing fasteners holding water jacket covers on outboard motors and my batting average isn't much higher than 500.

An online search seems to favor heat cycling.

 

[deakin]

hair dryer doesnt do crap. not hot enough heat gun and some cycles of heat