After the winter my 2002 mercury 75 hp 4 stroke would not stay running it would start and run for about 20 secs, I left it for a few weeks and it would turn over but not start at all. I took it to a marina and he does not seem to be able to figure out why it will not start. He says everything looks good except there is no spark and he now wants to start replacing parts with out knowing what is wrong. I told him he needs to know what is wrong and with what before he just starts replacing things, anyone have any suggestions what to check thanks in advance
