Small Engines (Lawn Mowers, etc.): hondagxv530cc, speed nozzle, gxv

Question
I have a 2005 lawnboy zero turn mower with a honda gxv 530cc engine that pulsates when the blade is not engaged. how do I correct it.

Answer
when u mean pulsate,do you mean hunts and surges?  meaning the engine revs up and down not maintaining a constant speed?

it could be as simple as old fuel in the tank, or it sounds like the carb may need cleaning

IF you pull the choke part way out does the condition go away?  If it does you need to have the carb cleaned.  the high speed nozzle is partially obstructed.