# Vapor Lock???



## Smolenski7 (Nov 24, 2010)

Twice last year my 24" Ariens Deluxe quit on me for no apparent reason. To make a long story short I think it might be a simple case of vapor lock. Some people think it's vapor lock and other don't. I think it is vapor lock. I have several questions related to this.

1. The rubber seal on my gas cap http://www.amazon.com/Briggs-Stratton-799719-694260-799863/dp/B009VHEKWC is loose and falls out. I do place it back on every time I put gas in, but I was wondering if this could be the problem? The guy at my dealer says no, that this would only allow air in and help.

2. I am testing for vapor lock as I speak. The guy at the dealer told me to tighten the gas cap as tightly as I can. I did this and it clicked once, like the gas cap on my car does. I never heard it make this click before, is that normal?

3. Finally, the dealer told me to run the machine, with the gas cap on tightly, to see if it stalls out. He said that if it is vapor lock, it will stall every time. Is that right? I ask only because it stalled twice last year; all of the other times I was blowing snow it was great.


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## Zavie (Sep 23, 2014)

Sounds like it's not letting air into tank as gas goes into carb, so what ever you call it, yes.


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## scrappy (Dec 7, 2014)

Vapor lock is when the fuel is hot enough to 'boil' and turn into a vapor, so doubt a snow blower is experiencing that.

If the cap is not vented, it can and will cause the fuel to not flow out of the tank. More like a 'vacuum lock'. 

So when the engine cut out what did you do to get it going? If it was vacuum locked simply opening the cap would allow fuel to flow.


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## Smolenski7 (Nov 24, 2010)

The guy at the dealership, who I doubt actually works on the machines, called it vapor lock. However, it sounds like your (Scrappy) description of "vacuum lock" is more like it. 

After the first time it happened I didn't know what to do since it caught me so off guard. I new the machine was a bit over due for an oil change, so I changed the oil and added a little gas. The second time it happened, I simply checked if it ran out of gas and let it sit for a few minutes. 

Both times I opened the gas cap and it ran fine afterwards. This was in February. The machine didn't experience anything after that. Even today, I let it run about 30 minutes and it ran fine. In fact, it started on the first pull without hesitation.


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## scrappy (Dec 7, 2014)

What engine is on this?. There was a recall er something for the LCT caps.


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## Kiss4aFrog (Nov 3, 2013)

First things first. That Amazon link is carzy expensive at thirty bucks. Here you go with a new one for twelve bucks shipped to your door: 
*Briggs Stratton OHV Engine Motor Fuel Gas Cap 799719 Fits 694260 799863 New | eBay

*I understand yours is a brigs but thought the video might help.


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## Smolenski7 (Nov 24, 2010)

scrappy said:


> What engine is on this?. There was a recall er something for the LCT caps.



It's a B&S 250CC Polar Force 1150.

Here's the parts manual: http://bsintek.basco.com/BriggsDocumentDisplay/18kvxIXRnfBhU7y.pdf


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## Smolenski7 (Nov 24, 2010)

Kiss4aFrog said:


> First things first. That Amazon link is carzy expensive at thirty bucks. Here you go with a new one for twelve bucks shipped to your door:
> *Briggs Stratton OHV Engine Motor Fuel Gas Cap 799719 Fits 694260 799863 New | eBay
> 
> *I understand yours is a brigs but thought the video might help.
> ...



No kidding! Crazy expensive. I would never spend that on a gas cap. 

Great video. Could the fact that the loose rubber seal on my cap causes the problem?


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## bwright1818 (Dec 2, 2014)

Does the machine have its proper shielding around the carb, that allows the muffler to heat the incoming air? Carburetor icing is a possibility, if it's not there. This is when the cooling affect of the air vaporizing the fuel in the venturi, freezes moisture in the air, slowly reducing the carb throat diameter to zero, because of ice formation. The engine looses power, then stops. In just about the time it takes to scratch your head and say, "Whaaa?" the ice melts and you're good to start her up again. How often this happens depends on the outside temp AND the moisture content of the air; so sometimes it will happen and sometimes it won't. Maybe this is your problem. Just a thought....


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