Murray MTD loses power when it is running Powers up and down?
This is usually a carb problem. It is not getting enough fuel
fast enough. Try spraying the carb out with carb spray. Take the
little float bowl out and let the spray run through it. This way
you can spray the bottom out also. If this doesnt help then you
will have to take the carb off and clean it really good. Use carb
spray and some copressed air for best results. Good luck.