'87 Johnson - Spark Adjustment - J30ELCUB

[Jim Hawkins]

'87 Johnson - Spark Adjustment - J30ELCUB

Hello, while out the other day I began to lose the upper end of my throttle control. Looking at the motor, I found the spark adjust screw had vibrated it's way in to a point it was restricting advancement of the throttle. I moved it back out and the situation soon repeated. To get by for the afternoon I moved it all the way out and wrapped a rubber band around it to hold it in place.

Now I would of course like to set this screw to the proper adjustment but the engine did not appear to run any differently with the screw backed out all the way.

Can anyone enlighten me on the workings of this screw?

 

[gm280]

'87 Johnson - Spark Adjustment - J30ELCUB

Hello, while out the other day I began to lose the upper end of my throttle control. Looking at the motor, I found the spark adjust screw had vibrated it's way in to a point it was restricting advancement of the throttle. I moved it back out and the situation soon repeated. To get by for the afternoon I moved it all the way out and wrapped a rubber band around it to hold it in place.

Now I would of course like to set this screw to the proper adjustment but the engine did not appear to run any differently with the screw backed out all the way.

Can anyone enlighten me on the workings of this screw?

It seems it is now so loose that it will continue moving. So what about using a lock nut to stop any movement? Or even setting it with some Loctite to keep it from moving after you get it adjusted to the correct place. JMHO

 

[Jim Hawkins]

It seems it is now so loose that it will continue moving. So what about using a lock nut to stop any movement? Or even setting it with some Loctite to keep it from moving after you get it adjusted to the correct place. JMHO

Of course, but the main thing is how to adjust it before I stop it's movement. Thanks.

 

[gm280]

Of course, but the main thing is how to adjust it before I stop it's movement. Thanks.

Can you see any evidence on the threads where it was originally set? If so I would figure that would be the correct place to reinstall it. Other then that, you probably need to buy the factory engine specific shop manual for your engine and see what it suggest to tune your setup correctly. JMHO

 

[racerone]

And what happened to the lock nut that was installed at the factory ?

 

[Jim Hawkins]

And what happened to the lock nut that was installed at the factory ?

Probably down inside the lower motor cover. The parts diagram shows a lock washer and nut. Of course that still doesn't help me with the adjustment but someone on here will know, they always do!

 

[racerone]

Looked at one of these motors and it says 30 degrees max timing advance on the sticker.

 

[Jim Hawkins]

Looked at one of these motors and it says 30 degrees max timing advance on the sticker.

Are you saying that turning that screw will set the timing advance?

 

[racerone]

I would hope that is what you will understand.