Re: Air In Fuel Filter?

Posted by Craig Hendrickson On 2009/10/16 15:12:41

Today's gasoline is much more volatile due to alcohol/methanol mixed in and probably other blending considerations. This is evidenced by carb fuel bowls drying out after a few days.

Maybe this explains "air" in the filter bowl. As the gas evaporates out of the carb fuel bowl, this releases pressure on the needle due to float drop. Any residual pressure (even gravity) in the incoming fuel line would cause fuel to be transferred into the carb, but since the fuel pump is not running, fuel or alcohol state changes to vapor causing the fuel level in the filter bowl to drop being replaced by gasoline blend vapors, i.e., "air".

Craig