Riding Mower, Fuel puking, big white smoke.

[twinrider1]

Mower suddenly belches out giant white cloud and stalls.
Pull air filter cover and air filter.
Start engine.
Fuel suddenly pours into the air intake from....not sure what it's called. It's metal, described as carburetor cover. My hunch is it's some kind of carb vent, vapor return.
Engine stalls out, white cloud.
(Briggs & Stratton Model 311707/0132-E1)

My hunch is the float needle isn't seating properly. But man that fuel is really flowing. I'm surprised it can flow that much fuel so quickly.

Anyone with small engine experience out there? Thanks.

 

[Zenmervolt]

Sounds like a stuck float to me. I'd pull the carb and have a look at it.

ZV

 

[weadjust]

Float is sticking open. The crankcase is probably full of oil. Pull the oil dipstick and smell it to confirm gas in oil. If gas in oil change oil. Simple fix is to install a fuel shut off valve in fuel line. Turn fuel on cut grass. Turn fuel off when the mower is not running. I have tried to solve the float sticking and flooding the crankcase on two different B & S motor and have failed even after buying a carb rebuild kit and replacing the float. Your better off these days spending $75-100 on buying a new carb than $40 bucks on a carb kit.

 

[twinrider1]

I'm seeing $120+ for a new carb. Seems they've gone up a lot, like everything else these days. It's not the first time I've heard rebuilding them is a crap shoot and not worth the time.
I'm going to add the shut-off valve tomorrow morning. Good idea in general and I hope it will let me get the lawn mowed as a stopgap until I can address the carb. You can't skip a week this time of year.

 

[weadjust]

Check price on amazon and ebay. I bought a new 2 barrel Nikki carb for a B&S motor for $100 w free shipping 2 weeks ago. All the parts places and online sellers list price was $150

 

[twinrider1]

The shutoff valve is doing the trick. Drained a crap ton of gas/oil and added fresh oil. No more gushing fuel. Makes me think maybe there's a crankcase vent and that's where the gushing fuel was coming from. It was just too much fuel to just be coming from the float bowl.
Welp, this will get the yard mowed for now. I'll keep an eye out for a carb.
Gracias.

 

[weadjust]

I have an old Murray with a B & S at my camp house that has the same problem. I have been using a small pair of vise grips as a fuel shut off valve for about 10 years.

 

[Mandres]

I have an old Murray with a B & S at my camp house that has the same problem. I have been using a small pair of vise grips as a fuel shut off valve for about 10 years.

Lol, that's one way to do it. I love me some vise grips - I've used mine for everthing ... They hold open the hood on my jeep since the struts failed, and they made a pretty decent clutch lever to get me home after I laid my bike down. They belong in every redneck tool kit along with the duct tape and bailing wire.

 

[Lounatik]

Also, try using real gas instead of the 10% ethanol stuff. Ive heard that the ethanol can wreak havoc in small gas powered engines. Google " ethanol free gas stations" to find one near you.


Peace


Lounatik

 

[Meghan54]

Also, try using real gas instead of the 10% ethanol stuff. Ive heard that the ethanol can wreak havoc in small gas powered engines. Google " ethanol free gas stations" to find one near you.


Peace


Lounatik

You know, I've "heard" that for years upon years.

First, you realize ethanol has been in gasoline for decades, it's nothing new.

Second, show me an engine manufacturer that will void the warranty on the engine using 10% or less ethanol laced gas. Hell, even my old 1985 Chrysler LeBaron convert approved the use of 10% ethanoled gas, and it's now approaching 30 years old.

Third, while there are horror stories about engines blowing up/failing from ethanol gas, I have yet to see one personally. And I've run small engines from Honda, Kohler, B&S and Mercury and Johnson/Evinrude outboards for years without problems.

I think you'll find most problems all come back to dirty/stale fuel, fuel lines not approved for ethanol use, letting the carb accumulate gunk from ethanol's cleaning properties and dirty gas tanks, which leads to said gunk in the carb bowl.

I do understand fully that ethanol burns hotter than gas, but the engines produced over the last 2 decades at a minimum were all designed to be exposed and used with ethanol-laced gasoline.

Think about it. If ethanol was destroying engines every day, all day, the repair shops would be overrun with blown up engines, be it a small engine repair shop or marine repair shop. Yet, you see 10 year old, 20 year old, and even older outboards and mowers/generators/etc. that are still running well despite using ethanol.