1971 Johnson 125 hp Ignition Help?

[J2EA2Z]

Engine runs well at mid to top end speed for 1/2 to an hour. Iles well to begin with. When you back it off close to idle after warmed up, it wants to run rough then die. Carbs. are clean. Idles well at first. Could it be pulse pack, coil or rotor cap overheating? And how might you test these with or without being warmed up? Thank you for any info.

 

[Daviet]

Re: 1971 Johnson 125 hp Ignition Help?

Use an inductive timing light to check each plug wire when it is acting up. That will tell you which cylinder or cylinders you need to look at.
Usually if happens only when warm you have an electrical component breaking down.

 

[Daviet]

Re: 1971 Johnson 125 hp Ignition Help?

Oh, by the way, welcome to the forum.

 

[Faztbullet]

Re: 1971 Johnson 125 hp Ignition Help?

This model is very voltage sensitive so check that engine is charging correctly as a drop in voltage can cause pack to act up. Also use a DC ammeter on purple wire to pack when acting up.if pack is drawing more than 1.8 amps replace pack.

 

[J2EA2Z]

Re: 1971 Johnson 125 hp Ignition Help?

Thank you guys.