The blower is about 5 years old and was running like a top until this
winter. It would run perfectly for a half hour or so then stall out.
The wife told me that she had solved the problem by simply topping up
the gas. I thought she was nuts, but that's exactly what it's doing. I
thought perhaps the gas cap might not have been allowing air in to tank
as the gas was used but when it started stalling I loosened the cap and
it did not help.

So in a nutshell if I top up the tank it will run perfectly for about
one inch of fuel then stall. If I top it up, it's good for another
inch. and so on! (I was thinking that I could simply move the tank up
about the height of the tank and my problems would be over) But I am
more interested in finding out what you think might be going on here.

Any thoughts would be appreciated.