It certinly sounds like the diaphram. Well worth a new one (aftermarket) for
under $5.
"donald girod" wrote in message
...
I have a Briggs lawn mower, solid state ignition. It runs normally (good
power, etc) once it starts, and it starts eventually, BUI...

I have to pull many, many times, and after a while the engine starts to
fire weakly. It will fire weakly 10 or 15 times and die, each time doing
a little better. Finally, it fires weakly, doesn't die quite, and slowly
picks up speed. Then it takes off and runs. It will restart readily when
warm, but if left even 10 minutes, it reverts to the painful starting.
The spark is strong (obviously), and I can see gas splash up in the carb
throat when I take the air cleaner off and pull the rope. When it does
start, it does NOT throw black smoke, as it would if the carb was
seriously loaded up with gas, in fact, it throws no smoke at all, and I
would bet that in fact it has been starving for gas. Maybe.

I have seen other Briggs engines do this, and I have never figured out
what the problem has been. I have done things like take apart the carb
and put in a carb kit (mainly, new diaphragm gasket or whatever that thing
is called), and sometimes I have "cured" the problem. But if somebody
recognizes this syndrome and can tell me what the most likely problem is,
I would surely appreciate it.