I have a 25hp johnson outboard model# 25r77s that ran fine 2 weeks ago, but when i went take it out this morning it would not start and had no spark. I do not know much about working on motors, and cant afford to take it to the shop, I was wondering where to start to try and fix the problem. I have already ruled out the kill switch, but that is as far as i know to check. Please help!