Late 70's 10 hp Briggs and Stratton engine questions

Recently purchased a 5000w Generac with it's original 10hp Briggs and Stratton. The original owner bought it new for a hunting cabin and used it a few times circa 1978 or 1979, then it sat in a basement for about 40 years. The fuel lines were replaced in 2004 going off the date codes on the rubber. The gas in the tank smells like turpentine. Oil is on the stick and still caramel colored. The original owner passed on, and his son was at the auction where I picked this unit up. He stated after I won it that it was literally used about 3 times and never used again, however the '04 fuel lines suggest it might have been used briefly or the guy tried getting it running about 15 years ago. Still has a fuel filter and fuel cut valve.

Anyhow, I'm going to remove the tank and flush the old gas out, replace the fuel lines and fuel filter, get a battery on it (electric start or pull cord) and change the crank oil. However, I'm unsure how to proceed with the carb on this unit? Do they have a diaphragm in/on them like the more modern push mower B&S engines? How does the fuel get pumped on these? Given the age, I doubt the carb will run the engine w/o issues as-is, especially if it has a rubber diaphragm to move the gas. Are parts for these still available? Can I retrofit something else if need be?


Model "251415"
Type "0196-01"

That is a Flow Jet Carb.
Screw the knurled knob ( main jet ) in till it lightly touches & write the number down
Then remove the entire tube using the hex BEFORE YOU TAKE THE BODY APART .
When it is apart you will see the tube which is thin brass passes through the bowl all the way up to the idle jet & thus is easily broken
Get the engine numbers off the cowl near the spark plug then go to the B & S web site & Download your parts manual.
You may be able to get a owners for it as well.
It is a sort of standard bowl carb

Thanks. Between the Flow Jet name and model number for the engine, was able to find carb rebuild kits and aftermarket carbs.

Try cleaning it first
They are a lot more robust then most of the modern EPA certified carbs.

I note the fuel shutoff on the fuel line. Might fill with clean gas and run like new? I have a similar generator that hardly gets run and when I give it a test run it can take several minutes for the generator to actually start putting out power. 'Don't assume it's just dead if yours does this.

Tank outlet to fuel filter, was basically clogged. Tank was nasty. Carb was surprisingly clean though. Jet was clear.

After cleaning everything, wouldn't start. Adjusted the float as the bowl was dry, and it fired up.

Runs good but has it's moments. Probably the first time it's run in 15 to 40 years :thumbsup:

tom3 said:

I note the fuel shutoff on the fuel line. Might fill with clean gas and run like new? I have a similar generator that hardly gets run and when I give it a test run it can take several minutes for the generator to actually start putting out power. 'Don't assume it's just dead if yours does this.

Click to expand...

Thanks, I'll keep that in mind.