1962' 50529A Starflite IV Magneto Ignition Weak Spark

[indiadamjones]

Evinrude Starflite IV with magneto distributor style ignition. The engine looks like the 50525 model, The serial shows model 50529A

I suspect I'm getting ready to remove the magneto assembly for rebuild. I built the air gap tester with finish nails and the spark looks weak and intermittent. I did eventually achieve a spark on all four leads, but not consistently, and I had to reduce the gap less than 1/4" to achieve that. That was done with plugs pulled. I've got a hunch that a 60-year old coil could use replacing, but I'd rather take a look first. I was having trouble starting when hot, which is what led me to take a closer look at the ignition. I just want a strong, consistent spark so I can worry about one less thing. Also, I couldn't get a video of all four sparks in one video.

Perhaps someone with more experience on these old Evinrudes knows where to go next here, or if distributor removal and inspection seems warranted. Thank you!

Note: Neighbor using loud 4750 watt generator in the background.

View attachment web-Spark 1-1.mp4
View attachment web-Spark 2-1.mp4

 

[racerone]

Replace breaker points and condenser and rotor.-----If that does not fix it perhaps the coil is aged and cracked.---Spark would jump to ground.----Removing the magneto requires marking the parts so the belt timing can be set correctly on assembly.

 

[F_R]

Oh. I couldn't figure out what the funky sound was. You are cranking it with the recoil starter. Duh. Anyway, if I were doing it. I'd remove and go through the entire thing. Could have a cracked coil and/or arcing through the side to the case. Or a pin-holed distributor rotor arcing through to the shaft. Or a missing carbon brush. You just gotta get in there and examine it.

 

[indiadamjones]

Thanks for the go-ahead. Surprise, look what I found! Seems someone allowed a critical wire to get a little too close to the pully! That's no way to get electrons to the plugs.

 

[indiadamjones]

That's not all! Looks like someone threw this coil on a belt sander to get better fitment. Well, that's great but look at the discoloration on the coil, and the pitting in the magneto housing.

 

[racerone]

I think that coil left the factory that way.----Not the issue I believe.----Clean the points, replace condenser.---Set breaker points using a meter.----Test magneto BEFORE installing it on the motor.----Spinning the pulley by hand should give you spark like a small electrical storm.

 

[indiadamjones]

Eureka!
View attachment spark-3.mp4

 

[racerone]

Good work.----No parts needed I assume.----Some of this stuff ( magneto ) here is simpler and more reliable than miniature electronics on new motors.

 

[indiadamjones]

@racerone Thanks, I bought a new gasket for the housing and replaced a couple of woodscrews someone used for the pulley cover. Probably will replace those points and rotor for next season on your recommendation. The condenser is somewhat new, and I've got an extra. You saved me on the coil, I got a refund on it this morning. Thanks again.