Hello, I have and old (80's) commercial walk behind 52 inch J.D. that I'm having inconsistant starting problems. It has a 14 horse kawasaki that right now has no spark. I use it to mow my 2 acre lot. Mowed about a month ago and had trouble then, but kept trying and messing with it's 5/6 safety switches and suddenly had spark and started and mowed for an hour and a half fine. Today tried to start to mow and no spark, no matter what I've messed with. I just took this in late last fall to dealer for ruff running and 350 bucks later this.... Seems like every year and a half or so have to take it in for about the same money. Its old and cost some, but it is also big cut and fast when working. Any ideas? Has anybody tried to download or find a service manual for something like this? Thanks bob