I have two, make sure the condenser is ok (or even there on one of mine) clean the points and set to 20 thou (0.5mm) to do this you have to remove the housings and the flywheel.
grendel
July 2011
I had the same problem you must make the point are completely clean and set to 20 tho.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix lawn mowers.