Engine Runs without Air Supply

Old Briggs and Stratton huh?......well, Hole in the fuel line (unlikely), the most likely is a hole (damage or rusted) in the filter housing. Where it it has more then one air intake

Somewhere, you have an air leak.

Gaskets maybe.

Spray WD-40 on the carb parts and the carb/intake and the leak should become apparent when it's running.

I prefer carb cleaner. Tends to make the revs increase when it gets extra fuel. Does WD-40 burn well? I've not yet tried it.

By the way, I found carb cleaner makes a good penetrating solvent when loosening corroded hardware. It wicks into damn near everything.

I have also read somewhere that you can make a good penetrating solvent using 50/50 acetone and ATF.

WD-40 burns just fine. My uncle used it to start his diesel tractors after he worked on the fuel systems with mechanical pumps.

The MSDS says it's a category 1 flammable aerosol. Whatever that is.

you want penetration, in my experience, this is second to none. Expensive, but good.

I've spent my money on Kano on two different formulations of their Kroil products, and while I would say that it works well, I don't think it works much, if any better than any number of other penetrating oils on the market. Kano just has better advertising. They are all based on a mixture of hydrocarbons including a volatile component that makes it extremely low viscosity that once the lighter fractions evaporate away, the lubricants left behind make the lubrication possible.

If you do a web search on "Workshop Magazine April 2007 penetrating oil" you will get oodles of hits referencing an experiment where allegedly the magazine authors executed a study to compare the efficacy of various penetrating oils. All sites seem to reference this article but I cannot find it.

Some people don't seem to care for PB Blaster because of complaints of gummy residue left behind. I've used Kroil, Liquid Wrench, PB Blaster, and some no name brand stuff I got for almost nothing at a local surplus store but I have not yet mixed the 50/50 ATF/acetone. Even the no-name brand stuff works just fine. I do agree that the PB Blaster does seem to leave behind a gooey residue. My impression of Liquid Wrench is that it seems to penetrate well, but there is not much lubricant left behind. I'd bet some Marvel Mystery Oil cut with some acetone would probably work like the cat's meow too.

Aahhhh, you must of bought the wrong one or applied it incorrectly,.... Ya, that's it...... ;p

I know! I know!

I had an old girlfriend who would run with Air Supply . . . .

on her walkman.

well, that certainly narrows it down "TO EVERY GIRL IN THE EIGHTIES"

Don't we know

It depends upon the type of carburetor but typically there is an o-ring gasket at the base of the idle jet adjustment. If that is missing then there is an air path that bypasses the carburetor inlet. Similarly there is a bit of play around the bearings that support the throttle plate shaft so air can also leak in there.

Let us know when it starts running without fuel as well.