Small Engines (Lawn Mowers, etc.): mower dies under a load, brigs and stratton, snapper mower

Question
Brigs and Stratton 18.5 hp model 31P777 type 0121-B1  on a snapper mower  with a snow blower attached.  When under a load, it dies and will only run at full throttle and full choke, it dies frequently, and after several minutes of re-starting, it comes out of it and i can take the choke off and it runs fine until the next time the engine lugs.  I have cleaned out the carb, replaced the vacuum fuel pump and fuel filter, drained the fuel tank and refilled with fresh fuel.  It also pumps out a bit of oil out of the vent on the fuel pump.  Could it be the solenoid on the bottom of the carb?  Any suggestions?   Thanks

Answer
Not the solenoid...these things either work or don't work.  If they don't work the engine will not start.

Have you cleaned the valve breather?  The oil coming out of the fuel pump vent may be an indication of a crankcase leak problem.  Are the intake gaskets in good shape?  Do you have a compression gauge to check the engine compression?

I'm betting the problem is the carburetor...99.9% of problems these days are carb related.  When you cleaned the carb did you blow compressed air from an air compressor through all the carb orfices?  Sounds like the carb high speed circuit may be obstructed not supplying enough fuel.

Eric