Hello, I bought a 1987 Stratos with a 1978 150 Evinrude. Cannot see a spark when it turns over, any help is appreciated. FYI the starter seems to be dragging a little so I am replacing it asap.
On a 45 year old motor like that the first thing is a compression test.-----Post your numbers here.-----These motors were famous for broken piston rings.-----I know that this has nothing to do with spark.-----But those results are good for future reference.---If starter cranks slow there will not be a spark----So charge the battery.----Load test battery ( even if new ).-----Inspect battery cables.----Myself I would take a starter apart for inspection before spending beer tokens.
It is not hard to figure out what is wrong if you follow suggestions.-----Even if these suggestion seem strange to you.----Disconnect black / yellow stripe wire at both powerpacks.----See if there is now spark when cranking .-----Test ohms on ignition charge coils and sensor coils.----No need to remove flywheel for those tests.----Load test the battery !
I am willing to learn, just never had an outboard. Plus whomever had the boat before me at some point did some really interesting wiring so I may just get a mechanic to take a look.
Do the compression test before hiring a $100 / hr expert.------The ignition system does NOT use 12 volts from the battery to make spark.-----But that is a mysterious fact to some.----The previous owner may have been stabbing in the dark.----I was not there !---Spark comes from the electronic magneto if flywheel spins over 250 / 300 RPM.
It works like a crank trigger used on race engines I know, I'm looking for a wiring diagram also to trace the wires that look factory and try to figure out why the extra wiring.
Many different opinions on compression.-----I would be concerned with those numbers on my gauges.----Then again it may have a ---" low compression kit "---Installed on it.