87 marinre 45

[mariner45/15]

I have been given a boat with a 45 mariner on it. I can get the starter motor cranking but have no spark at the plug. tried the kill switch in both positions (just in case). Looks like a different ignition system than a small motor, fuel is not an issue. It has been outside in the canadian climate for 3 years. this is my first motor and cant seem to make it run. any tips on what to look for or what to try?
Thanx Baffled