Vapor lock

[StarTech]

The temperature the fuel boils depends it formulation. Winter fuels are more volatile in nature. Plus depending on the formulation gasoline can boil as low as 140F. Also the Spring, Fall, and Winter month carb icing can be a problem too. I have had aircraft carburetors to ice over @ 70F depending on the amount moisture in the air. And it is scary for it to happen over a larger city with no place to land.

 

[ILENGINE]

Just make sure the gas tank is vented. The cap has a small hole, make sure it is clear.

After 2012 most caps are not vented They use a separate vent system that is connected to the air intake on the engine. Some push mower caps are vented with a charcoal filtration canister built into the cap. Which can get gas contaminated and brick the material making it not vent.

 

[smhardesty]

Do a google search for "pure gas" to locate a station in your area

Yep. I have found that I have fewer problems with my fuel systems when I use only "pure gas". There is only one station in my small city of under 10,000 that has pure gas. I found that station via the site in the link below. Check it out for your town/city.

https://www.pure-gas.org/
.

 

[lbrac]

You didn't describe the issue you are experiencing. Vapor lock is caused by a liquid being heated enough to cause it to vaporize. When it cools enough, it will go back into liquid form. Like water, if it is under pressure, it takes a higher temperature to vaporize. Rerouting the fuel line away from heat sources could help, or wrapping the line with insulation, like fiberglass, can help. Manufacturers don't usually route fuel lines near a source of heat that will cause vapor lock, but someone else could make that mistake.

 

[Tbone0106]

I have an older Sears generator that's powered by a Tecumseh 6 hp horizontal shaft engine. (Similar to the one in the pic.) If you look closely, the fuel line from the tank on the back to the carb (which is absent in this pic.) actually passes THROUGH the starter shroud, right past the cylinder. This bad boy always ran like a champion until that little quart-sized fuel tank ran dry. Then, once the flywheel stopped and the cooling air ceased to circulate, that thing was the King of Vapor Lock. I couldn't start it again for at least a half hour, though once that vapor bubble went away, it always started right up and ran like a top until the tank went dry again. Lather, rinse, repeat.....

I was able to completely solve the problem by installing a new fuel line on the outside of the shroud.