I've been reading some posts here that reference the plastic star wheel on top of the carb on Lawn-boy push mowers and how to turn it clockwise to increase performance. I have a Lawn-boy model 8480 (got a new 10550 on order as well) and I did exactly that and my mower and the RPM's of the mower certainly appeared to increase. I'm not a mechanic, but I would like to know exactly what is being done when this wheel is adjusted. I'm guessing it's increasing the air flow/fuel mixture, but I'm not sure. Also, is there any danger of damaging the engine by doing this?