1971 Evinrude Lark 50hp 2 stroke No Spark

As the title states I have a 1971 Evinrude Lark 50hp 2 stroke. That?s not getting a spark. The motor cranks fine but, I can?t seem to get a spark/ark out of the spark plug wire. The motor ran fine last year and put is away for winter (dry storage and winterized). When I pulled the boat out for spring the motor would not fire up.

I?ve replaced almost the entire ignition system including: spark plugs, ignition coils, power pack, rectifier, stator, spark sensor (on the timing base), 20 amp fuse, and the key switch.

Step I?ve already take to trouble shoot are tested with a digital ohm meter all cables coming from the power pack and the terminal block, Disconnected the internal wiring harness and tried jumping the motor off of the starter solenoid, tried using a different battery, removed black and yellow wire from the power pack and tried starting.

I do have the original manual and troubleshooting guide for this outboard.

I?m at a loss as to what is causing my problem since I have the same problem when I started as I do now.

Any help would be greatly appreciated.
Thank you.

Re: 1971 Evinrude Lark 50hp 2 stroke No Spark

Have you got the wiring diagram for your motor? The neutral safety switch could kill the spark. Try jiggling the shifter handle a little, and also making sure the warm up lever is all the way down when cranking. On my '72, if the warm up lever is all the way up, it won't get spark. I don't really know why......
That system has a lot of parts that can kill spark, and you'll have to go through it step by step with the wiring diagram.
Good luck---- I'm no electrical expert myself, and hate having to figure this kind of stuff out, too.
JBJ

Re: 1971 Evinrude Lark 50hp 2 stroke No Spark

Thanks for the help unfortunately I don't have a warm up lever. I do have the complete wiring diagram and am about 2/3 the way through testing all of the wires. I'll check the safety switch.

Thanks,
B

Re: 1971 Evinrude Lark 50hp 2 stroke No Spark

I have the same motor you do. I am pretty sure the safety switch does NOT cut the ignition (only the starter circuit). I would suggest making certain your ground connections are good. Also, as I recall, the ignition circuit runs through the ignition switch. If the contacts in there are not properly conducting the ignition power when you are cranking the starter, your engine will not fire. I bought my boat and motor as a non-runner. The only thing I had to do to get it running was to take apart the ignition switch and clean up the contacts. Good luck.

Re edit: Sorry didn't catch the part about you replacing the ignition switch. But the ground connection solution may still be valid. Also ensure the connections on the terminal bus are all good and nothing is broken. Kinked wires or wires with the plastic covering broken can take in moisture and corrode from the inside but still look good on the outside (been there, done that). If it was me I would start at the battery and test for voltage or resistance from there through every wire and component to the coils. I feel your frustration. I'm sure it will turn out to be a broken wire or bad connection.

Re: 1971 Evinrude Lark 50hp 2 stroke No Spark

Thank you, I working on going through all of the connections right now. Will post what I find.

B