Briggs carb question

rrman61 · Jul 15, 2020

I was given a not running trail mower with a 21 HP Briggs and Stratton engine.I’m about to clean the carb.What does the 2 wires attached to the bottom of the bowl do?i see one is a ground.

1948jr · Jul 15, 2020

I think it shuts gas off and keeps it from backfiring when u turn it off

J Hamilton · Jul 15, 2020

Fuel shut off solenoid. The best thing to do with that is take it off, snip the end off, reinstall and put a manual inline fuel shut off on the fuel line. Just remember to turn it off when not in use.

Billy Shafer · Jul 15, 2020

Correct fuel shut off. The power is cut. The solenoid is no longer powered. Spring inside closes the needle valve cutting off the fuel.

rrman61 · Jul 15, 2020

If it works,would it kill the engine pretty quick or does it shut off fuel from filling the bowl? I’m thinking a quick kill switch grounding out the coils would work better as this is a mower that I might need to stop quick.

J Hamilton · Jul 15, 2020

Should have a tab on the side of the shroud to ground the coils for a quick stop

wore out · Jul 15, 2020

(quoted from post at 10:20:25 07/15/20) If it works,would it kill the engine pretty quick or does it shut off fuel from filling the bowl? I m thinking a quick kill switch grounding out the coils would work better as this is a mower that I might need to stop quick.

To add to what the other guy said, when de-energized it cuts off the flow of fuel from the float bowl to the main jet to prevent unburned fuel from passing through the engine as it coasts to a stop to prevent hot muffler "backfire" and to reduce air pollution.

Does NOT affect fuel entering the float bowl through the float valve needle and seat.

Typically, the engine is stopped by grounding out the ignition system AND releasing the main jet cutoff solenoid at the same time. An ignition switch set up for this setup is required to make that happen.

rrman61 · Jul 15, 2020

Got it thanks guys

Steve@Advance · Jul 15, 2020

When you clean the carb, be especially careful to really clean the main jet thoroughly.

That is usually what clogs when left sitting with ethanol gas in the system.

Blowing and spraying cleaner will not get it clean! It needs to be scraped out with a small stiff wire or a tiny drill bit that will fit through the hole. Don't enlarge the hole, but do take your time to be sure it is thoroughly clean.

guido · Jul 15, 2020

Hello rrman61,

Its an anti dieseling solenojd valve, ignition powered. Two wires, ground and power.

Case is not grounded,

Guido.

Two Dogs · Jul 15, 2020

J Hamilton · Jul 15, 2020

J Hamilton · Jul 15, 2020

After they start getting old they don't completely shut off and either stick open or closed.

T.R.K. · Jul 15, 2020

It usually takes 3 to 5 seconds to die after you cut the power.

mjsnodgrass · Jul 16, 2020

i believe it's some sort of fuel shut off valve. i just went through the carb on 21 horse briggs. didn't get it right the first time by just cleaning the main jet. the vertical brass emulsion has lots of tiny little holes. thats' where my problem was. used a real small torch tip cleaner. works great now. good luck

Briggs carb question

rrman61

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1948jr

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J Hamilton

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Billy Shafer

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rrman61

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J Hamilton

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wore out

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rrman61

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Steve@Advance

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guido

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Two Dogs

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J Hamilton

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J Hamilton

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T.R.K.

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mjsnodgrass

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