On Wed, 16 Apr 2008 19:30:10 -0700 (PDT), Manjo
wrote:

I have a leaf blower that uses a 5 hp B&S "L" head engine. The carb
is pretty simple with a choke butterfly, throttle butterfly, and
rubber diaphragm fuel pump. The carb sits on top of the fule tank.
The carb has no bowl. The governor linakges are clean and the
governor appears to be working fine.

The leaf blower was starting to run poorly last fall. This spring it
started right up, but after4-5 seconds after running smoothly at
proper speed, it will slowly loose rpms and finally stop after 15-20
seconds.

I have cleaned the pick-up tube, replaced the carburetor diaphragm
fuel pump along with the gaskets between the carb and the fuel tank,
and the gasket between the carb and the engine. I've also
disconnected the engine ground wire that normally kills the engine
when the throttle is tuned full off. But after doing all this the
engine still will not stay running for more than 30 - 40 seconds.

Thanks in advance for any tips, suggestions, or coments.

Manjo

Examine the spark plug or just replace it. Check for fuel /air mixture
adjustment. Make sure air filter is clean.

Compare sprak plug to this chart.

http://hawkworks.net/sparkplug-chart/