1971 20 hp Johnson Seahorse has no spark in either cylinder. Why?

[Buck Horn Deer Farm]

This 20R71S motor has no spark at either plug. Before I pull the flywheel, What could cause this problem on both cylinders? There are 2 wires out of the magneto that are not connected to any thing. There is a switch that the shift linkage pushes on when shifting into gear that has an empty male connector on one side and on the other side a wire to the solenoid I think. Where should these 2 wires go? And do they need to be connected to anythig for the motor to run?

 

[tblshur]

Re: 1971 20 hp Johnson Seahorse has no spark in either cylinder. Why?

buck horn while waiting on someone knowledgeable you can look at the sticky post at top of this page good luck.

 

[F_R]

Re: 1971 20 hp Johnson Seahorse has no spark in either cylinder. Why?

The two wires coming from the magneto are the kill wires to turn it off. If they are not connected to anything, you should have spark. Connecting them together (via the kill switch) kills the spark and it quits running.

The other switch is the safety switch. Prevents electric starting in gear. There is only one wire going to it, coming from the starter solenoid. Nothing connects to the other tab. The circuit is completed to ground through the switch mounting screw. No, it has absolutely nothing to do with your no-spark condition.

Time to pull the flywheel to see what's wrong.

 

[kfa4303]

Re: 1971 20 hp Johnson Seahorse has no spark in either cylinder. Why?

HI Buck Horn. Yup, sounds like you gotta pull the flywheel and inspect the ignition system. Not to worry, it's a simply DIY job. This link can walk you through a tune up from top to bottom.

Maintaining Johnson E & FD Serie

 

[Buck Horn Deer Farm]

Re: 1971 20 hp Johnson Seahorse has no spark in either cylinder. Why?

Thanks F R for the info on the switches. kfa4303 thanks for the link. Inspection starts this week.

 

[kfa4303]

Re: 1971 20 hp Johnson Seahorse has no spark in either cylinder. Why?

Here's another handy ignition rebuild link, or two. They're for slightly different models, but all the steps are the same for your motor. That's the beauty of the old OMC "universal magento" once you can work on one, you can work on any of them. Holler if you get stuck.

Magnetos

3 HP Evinrude Lightwin Ignition System Tune-Up 1952-1967

http://forums.iboats.com/johnson-evinrude-outboards/grandads-johnson-seahorse-10-a-506678-2.html