Do you drain the fuel from the machine before you put it away in the winter?
If not, you will most likely need a carb re-build. You can buy a kit to do
this from your local parts dealer. When I re-built my 5hp vertical shaft
Briggs, I threw the carb in the parts cleaner for a while, and it works like
a champ. So, before the re-build, take the carb off, and run some carb
cleaner through it. If that doesn't solve the problem, the next step would
be to re-build the carb.


"Bruce" wrote in message
...
I have a lawn mower with a Briggs & Stratton 5HP Quantum I/C engine
that suddenly developed problems. It's run great for the several
years that I have had the mower (bought it used) and the engine has
been well maintained during that period of time (regular oil/air
filter changes, stored inside and out of the weather).

Last Saturday, while cutting grass, the engine stalled. Each time I
pulled the cord and it would start immediately but quickly stall
(within a few seconds). This engine has a little rubber primer bulb
on the fuel tank that you can use to squirt a little gas into the carb
for a cold start. When I pressed the bulb repeatedly right after the
engine started and began to stall, the engine received enough fuel to
keep running for a few seconds. When I stopped pressing the primer,
it soon stalled.

At first I suspected that the main fuel line was blocked so I took the
air filter and holder off and detached the fuel line from the gas tank
(the primer bulb has a smaller, separate line that goes from it to the
carb). Fuel flowed easily from the tank through the nipple where the
main line attaches. Next I blew some compressed air into the fuel line
and a nice vapor of gas mist exited from the orifice in the carb. I
took the opportunity to blow out the air filter and pre-cleaner screen
(somewhat dirty but not too bad).

I put everything back together but the problem continues -- same
symptoms as before. Anyone have any ideas? I don't know squat about
small engine carburators (or engines for that matter) but would love
to fix this without a trip to the shop.

- Bruce
rbloth at yahoo dom com

PS ... In case anyone needs it here's the model/type/code for the B&S
engine:

126802-3423-01 92111658