1976 25 hp Evinrude lost fire after maintenace

[AFlowers]

Issue: When top plug wire was disconnected the motor would die. Comp test shows 120 on both cylinders. has two new (two week old) coils and plugs. I bought a spark tester and the top showed no spark at all. I pulled the fly wheel and knocked of the carbon from the magnets on the flywheel, sanded and reset the points to .20. Now, neither wire is producing a spark.

NOTE: While pulling the plug wire the spring-like connecter came loose from the plug wires (both), I reinserted the pin that juts from the connector back into the wire and slid the wire back down into the boot.

Also, the magneto looked to be intact but I took sand paper to the ends where they are closest to the fly wheel. It is shaped like an M and I sanded down the left, middle, and right. (Got a bad feeling about that one)

Could one of these two issues be the problem? If not, how can I work my way backwards to find the problem? I do get a back fire every now and then while trying to crank the engine.

 

[ronward]

Re: 1976 25 hp Evinrude lost fire after maintenace

I'm no expert on this but it seems to me that if you get an occasional backfire, then there must be an occasional spark to cause it. Just not at the right time. Did you make sure the points were on the high point on the shaft when you set the gap?

 

[AFlowers]

Re: 1976 25 hp Evinrude lost fire after maintenace

Yeah. There's a little box with the word "set" stamped into the shaft. It is just past the high point so I don't know if that is it or not.

Right now I'm trying to figure out how to do an ohm test on the coil that sits in there with the points. IDK if that will tell me anything or not though.

 

[AFlowers]

Re: 1976 25 hp Evinrude lost fire after maintenace

Good News - I got her running pretty smooth for the time being.

Cleaned the points spotless as well as all of the build up under there..

Bad news - I boogered up the shaft threads removing the fly wheel. Bought a new nut and got it torqued on. Lord help if I have to take it back apart. Hopefully she'll last until fall. Then I plan on a complete tear down and rebuild and will replace the crank-shaft unless I can find someone to re-thread it. If that's even possible.