the magnets on the magneto need cleaning and the pickup points on the coil . most smaller garden petrol engines use the same principal to generate a spark
the bloke is hard to understand but you will get the idea
watch this below it will give you an idea on what need to be cleaned. you will only need to take off the cover to access the magnets on yours , not all that he takes off
http://www.youtube.com/watch?v=ry-oBVC-Tt4
joe blogs, August 2011
