20hp Johnson 50th Anniversary - Firing issue

[KYFishin']

Hello all,

I have a 50th anniversary Johnson Seahorse 20hp. The 2 cyl. / 2 stroke motor is equipped with electric start and is a 1972(???) as far as I have been told. My Issue: I am only receiving spark to the lower cylinder. I am preparing to dig deeper today into the elecrtical system and was wondering if you all might have some advice? Thanks for any help.

 

[mikesea]

Re: 20hp Johnson 50th Anniversary - Firing issue

based on the age of the motor,I bet the coil has gone bad,there is 1 coil for each cyl.located under the flywheekl ,that can only be removed using a flywheel puller,there is also a set of points and condensor for each cyl.coils ,over time crack and loose spark potential,sooner or later they need change,parts are avail on iboats store

 

[KYFishin']

Re: 20hp Johnson 50th Anniversary - Firing issue

Thanks for the advice. I will go through and replace coils, points, and condensors since I have to pull the flywheel.

 

[tashasdaddy]

Re: 20hp Johnson 50th Anniversary - Firing issue

yep if you have to go there that is best. replace plug wires also. be sure that the shaft and wheel are totally clean and oil free, and torque the nut, to proper setting. if not you will be going back, as it will shear the woodruff key.