The engines in a murray sentinel ride on mower. It starts ok when choked and runs when you pull it back to full revs position but the revs fluctuate up and down and when pulled back to idle position runs rough and stops. I cleaned the carb out which wasn't to bad but the problem is still there. I also tried another plug with no change. This started happening quickly after running really well.(any ideas /)
Thanks.

Phil B., January 2009

clean out fuel tank could have water in it. fluctuate up and down with choke off means its running lean. not getting enough fuel .water could be blocking the fuel passage ways. seen this problem a lot.

bob, February 2009

It is a carb problem - most likely that the jets need taking out and cleaning completely. They gets bits stuck in them - grass very often through the fuel system. If you have adjustable jets, remove completely - blow through then screw in carefully till they stop and unscrew 1 1/2 turns to start up

eparkmowers, January 2009

seems to be too rich, did you take out the needle valves when you clean out the carb, if not remove them and pump air, or use carb cleaner you will have to remove everything to be sure. and also clean the air filters.

Tony, January 2009