Why does my motor only run with the choke on?

If a motorcycle or ATV only runs with the choke on, it’s because the richer “choke on” mixture is actually closer to the engine’s normal operating fuel mixture than the leaner “choke off” mixture. So when the choke is turned off, the engine gets too little fuel and too much air for it to run and it stalls.

Can a 5HP Briggs and Stratton run on full choke?

My 5hp Briggs and Stratton Horizontal, diaphragm carburetor, mechanical governor, will only run on full choke. It’s been out of service for 20 years, and I’m trying to revive it. I couldn’t get it to run at all with the original carb even after a thorough cleaning.

Why does my Briggs and Stratton not keep running?

Start the engine, and feather the choke so as to keep her running. Soon, you should start to see an improvement in the engine’s behavior (and probably TONS of smoke too, don’t worry, this is expected). See, gasoline oxidizes as it gets older, and forms a varnish on fuel system components.

Can a Briggs and Stratton Tiller keep running?

5hp Briggs and Stratton will not keep running… I have a BS 5hp model 135202 tiller and it runs fine with complete choke, but when backing off the choke it will die… I have taken complete carb apart and cleaned it thoroughly and installed new diaphram, dumped out old gas, and filled with new, and still will not run when choke is opened up.

What to do about a small Briggs and Stratton engine?

To test and fix, check out our Small Engine Ignition Systems FAQ or reach out to your local Briggs & Stratton dealer for advanced repair help. Air-fuel compression is crucial to engines powering lawn mowers and outdoor power equipment.

Why does my Briggs and Stratton engine not start?

A Briggs & Stratton engine relies on a few key components to start and run. These include air, gas and ignition. If your Briggs & Stratton engine has a spark but won’t run, then it is most likely a problem with the gas or air intake in the engine.

Why does my Briggs and Stratton Troy Bilt not run?

Engine will start if choke is closed, but dies when choke is opened. It will continue to run with choke almost closed for a short time, then it dies. I’ve verified that there is not a problem with the fuel line or filter. When the line is disconnected from the carburetor, fuel flows freely.

What kind of engine does a Briggs Stratton have?

Have just completly rebuilt a 12F802-1975-B1 briggs engine. All new gaskets, new air filters, completely cleaned carby (including venturi holes in the nut on the bowl), reseated valves, clean oil, new fuel – basically brand new inside and out.