1970 Johnson 115 eratic spark will not start

[farmuse]

I just recently purchased a 115 with electric shift. When I turn the key on to run position I can here current arcing in the distributor. While cranking it will not produce spark at the plugs, only intermittently will it spark at plugs. It is however a bright blue spark, but it does not necessarily spark during the compression stroke. While cranking and releasing the key and the end of a crank cycle it will fire, but I cannot get it to start. Could the distributor cap be faulty? I removed the Flywheel and the cap and when I turn the key to run position I can see the arc inside the cap.

What do I need to replace? or what could the problem be?

 

[farmuse]

Re: 1970 Johnson 115 eratic spark will not start

Can anyone help here?

 

[Daviet]

Re: 1970 Johnson 115 eratic spark will not start

A quick check, turn the key to the run position, use a jumper wire and jump the starter soleniod and see if it will start.
Your problem could be a defective ign switch, looses voltage to the ign side when in the start position.

 

[farmuse]

Re: 1970 Johnson 115 eratic spark will not start

I disconnected the ignition switch all together powered up the ignition from the battery and powered the solenoid from the solenoid (battery connection) to make the engine turn. when it was at the end of the crank cycle it would fire but still not start.

I can get it to fire but not run and only at the end of a start cycle will it fire. I let it turn over 10-12 times in a cycle. As I said I am getting intermittent fire in the crank cycle. still

 

[Daviet]

Re: 1970 Johnson 115 eratic spark will not start

I think that you should get the OEM manual and use the troubleshooting section to find your problem, it almost sounds like a pulse pack is going out. There are several componets that are associated with the pulse pack and could possiabley be causing the problem.

 

[farmuse]

Re: 1970 Johnson 115 eratic spark will not start

Problem solved. The two pulse wires running under the flywheel were shorted causing continuous pulse, IE arcing in the distributor
Running now on muffs. Will put it in a barrel tomorrow. For final adjustment before putting on boat.