Small Engines (Lawn Mowers, etc.): Briggs Stratton Quattro 4hp, briggs stratton, generac portables

Question
Hi
Neighbor gave me a Generac Portables Power Washer model 01467. It has a 4hp Briggs Stratton Quattro. The  throttle lever is off, rabbit or turtle. Going from turtle to rabbit there is no change in engine rpms. The motor runs, but doesnt rev up , spits and sputters . Doesnt seem to be firing correctly. I have read on the board, but cant see where the adjustments are. Are there carb adjustments on this motor to rev it up ? I have changed the oil, spark plug   (.30 gap)new gas and cleaned air filter. Neighbor says this is a "disposable" engine. THnaks in advance.  

Answer
Hi Jon,

Sorry for my delay.

Look in the carb throat to see if the throttle plate is opening when you advance the throttle lever.  You can try adjusting the carb jets but they shouldn't have moved from when it last ran well.

Let me know how you make out
Michael