Added a fuel shutoff valve to my 20hp Briggs V-twin

[Elkins45]

I alternate between two mowers. One has a replacement B&S 20HP V-Twin that I bought new 2-3 years ago and it only has about 25 hours on it. It had been sitting for about three weeks and when I started it up there was an incredible amount of white smoke that came pouring from the muffler and it continued for much longer than I would have expected and the muffler was much hotter than normal, along with a strong smell of unburnt fuel. Later I noticed that the under-hood gas tank was almost empty. My thought is the needle valve has already started leaking and the solenoid controlled fuel valve leaks too, so the gas had slowly leaked through into the cylinders and then the muffler.

I bought a bag full of fuel shutoff valves when I was working on other mowers and outboards so I ran it almost empty and spliced one into the fuel line. I already have shutoffs on all my other small engines but I figured the mowers with their solenoid shutoffs didn’t need them. Guess I was wrong.

 

[Racer4]

I did the same thing with my 24 year old Simplicity with a Kohler Command because of the same reason. It works as long if you remember to cut the fuel off and on.

 

[MurkyAsparagus]

I just did the same thing on the exact same engine this past week when I went through it, needle was green and looked horrible. When I replaced the fuel pump, I got a shutoff valve, a fuel filter, and new fuel lines for like $15.

 

[Drifter]

I installed shutoff valve after fuel leaked into the crankcase. Check your oil. I now turn valve off and let it run out of fuel.

 

[Elkins45]

I did the same thing with my 24 year old Simplicity with a Kohler Command because of the same reason. It works as long if you remember to cut the fuel off and on.

I probably need to put a sticker on the steering wheel LOL

 

[Mechanician]

When they flood this badly often fuel not only goes into the exhaust, but also past the rings and into the crankcase.

 

[Elkins45]

When they flood this badly often fuel not only goes into the exhaust, but also past the rings and into the crankcase.

Hopefully I didn’t run it long enough to hurt anything. It’s filled with straight 30 grade oil so hopefully it started thick enough that it could stand a bit of dilution.

 

[mk378]

The solenoid won't prevent the fuel bowl from overflowing into the intake. Gas will come out through the bowl vent rather than through the jets.

 

[repairman54]

1996 14.5 hp BS leaky solenoid valve carb will load up the cylinder, it loses sealing after years of vibration. After the second one wore out the shut off valve went in 10 years ago. Haven't touched it since.
At least my 17 hp BS with the fuel pump doesn't have that issue, just a longer crank to fill the carb up after sitting.

 

[ls1mike]

I have them on both my mowers. It is cheap easy insurance.