Re: 1968 Evinrude 55 No Spark
You need to isolate the trouble. First make sure you have nominal 12 volts at the amplifier with the key turned on (and cranking).
Then, remove the coil and unscrew the spark wire from the distributor cap, then remount the coil and rig up a spark gap off the end of the spark wire. Disconnect the wire between the amp and timer plate. Now, with the key turned on, lightly brush the wire that went to the timer across a bare metal ground. You should get a flurry of sparks from the coil's spark wire. If you do, then the amplifier and coil are ok, as well as other wiring up to that point, and your trouble has to be under the flywheel. If you don't get sparks, and you are sure of the 12V input, then either the coil or amplifier are no good. You can test continuity of the coil windings with an ohmmeter. Other than that, it is a crap shoot---coil or amplifier. It isn't a bad idea to replace the coil when installing a new amplifier anyway.
Just a thin bead of EP where the spring rides on the crankshaft.
I have the 1968 55hp Factory Service manual right here in front of me. It says 70-85 foot pounds on page 2-3.