I thought I was hot stuff after successfully rebuilding the carburetor in my
12 year old 3.5 hp Tecumseh mower last year. Recently my other Tecumseh
gave me problems at the beginning of this season with failing to keep
running. I would put gas in the carb underneath the air cleaner and it
would run for about 10 seconds and then cut off. I pulled off the carb and
replaced the float, the seat, the pin and rod. I also took off the welch
plug, cleaned under it and replaced it with a new one. There was all kinds
of the junk, including some crystals in the bowl and the float had been
stuck. After reinstalling it the mower would surge, so I readjusted the
float. I've done this twice and with the most recent time, the mower worked
for about 4 hours (3 different occassions). It would surge upon starting,
but then level off after a minute and I would mow the grass with no probem.
Now, it surges all the time at both low and high speed, but more at high
speeds. At high speed it eventually cuts off. I've done all the other
basics like new spark plug, air cleaner, cleaned the fuel line, etc. I
don't think the tension spring to the carb is the problem and I've been
using new gas. I think it might be that I haven't adjusted the float the
right way, but after taking the carb off at least 3 times I am kind of
running out of patience. Any help would be appreciated. I would like to
make it through another season with this mower before going out and getting
another one. Thanks,

Wade