The cap usually has a vent. It may be plugged.
wrote in message
oups.com...
On Aug 1, 1:59 pm, "Steve Barker"
wrote:
the only thing using a reed valve is a two stroke, and that would have
nothing to do with building a vacuum in the tank.

s

"David Martel" wrote in message

ink.net...



rile,

As gas is drawn from the gas tank air must come in through a valve,
typically a cheap reed valve. These valves can fail. So you run the
mower
until a vacuum builds up in the gas tank and stops the flow of gas.
Next
time it stops take the gas cap off, put it back on, and try to start
it.
If it starts up then suspect the reed valve.

Dave M.- Hide quoted text -

- Show quoted text -

Well, strange as it may seem, I may agree with the gas cap theory. I
had thought of that before. Everytime I take the gas cap off, it
seems to run for awhile and then stall. It seems to me that as the
fuel level goes down, there has to be a means to prevent a vacuum from
disrupting the fuel flow. Could it be a bad gas cap? I'd run it
without one as a test but don't like the idea of gas splashing out of
the tank onto the hot engine.