Johnson 15 Throttle Interlock Dog

[C0rnbreaded618]

I have a 1989 15hp Johnson J15RCEC. The guy I bought it off said it runs but something is off. I cannot move the throttle in any direction. I've found some information on similar year Johnson's having a throttle Interlock dog preventing the throttle from moving and/or preventing starting. I'm attaching a few pictures, do I have the red assembly correct?

 

[Pappy]

Yep, you do. That part should not impede the throttle at all but it will keep the flywheel from moving if you have your throttle advanced too far or are in gear vs being in neutral. You also have an idle speed adjustment knob on the end of your throttle handle. Try backing that out a bit and see if your throttle handle begins to move.

 

[C0rnbreaded618]

Thanks for the reply Pappy. It seems like either way I twist that adjustment knob I only get a little play out of the throttle handle. Is it supposed to move a lot?

 

[Pappy]

No....not supposed to move very much. It is just an idle rpm adjustment. Almost sounds like it is doing what it s supposed to do. but......
On the '89 model year engines you have a throttle cable. You can separate the joint where the cable moves the throttle advance assembly. Do this and see if the throttle handle moves easily and then see if you can manually move the arm the cable attached to easily. This will tell you what has to be looked at.
Put the engine in gear (engine not running) and try it as well....you should only have full movement in gear, limited movement in neutral.

 

[thill]

C0rnbreaded618,
Try putting the engine in forward gear. Then you should be able to move the throttle freely if the interlock is installed correctly.

When in gear, you should be able to throttle up, but not be able to pull the starter rope. It is a good safety feature.

When in neutral, you should be able to twist the handle very little, but you should be able to pull the starter rope.

You could have other issues, if the throttle handle is just locked in place. Try it in gear and post your results.

 

[thill]

I can't remember if yours has the solid gear or if yours is a cable. Very often, what is frozen is the vertical shaft against the powerhead that moves the linkage to the carbs and the timing base.

There are two hold-down tabs that hold that shaft. Sometimes, you can loosen those tabs, spray some WD40 all around them and get them to work loose. Sometimes the grommet at the bottom has bad corrosion around it, and needs a lot of cleaning out.

This is going from memory. I might need to go look at a schematic to give you better info. Hopefully, it's something simple and you have already figured it out.

 

[Pappy]

Thill.......look two posts up!!!

 

[thill]

Thill.......look two posts up!!!

A day late and a dollar short, ha ha!

You are on it. Good job!

 

[C0rnbreaded618]

Thanks for the replies, I'll report back soon.

 

[C0rnbreaded618]

When I put it in forward gear nothing really changes

 

[Pappy]

Okay......well you have been given some steps to take and have not taken them yet to help troubleshoot. Refer to post #4 and start there and report back to us.

 

[C0rnbreaded618]

Thanks for all of the information, I was able to finally get back at it.

I separated the joint where the cable moves the throttle advance assembly and it did move easily. It was indeed the vertical shaft and the corresponding plate/retainers under the flywheel.

I cleaned the corroded and stuck areas under the flywheel and it moves freely now. I have some triple guard lube coming today in the mail to lube it back up and reassemble.

Hopefully I'll be up and running soon.

Thank you all very much.

 

[Pappy]

Congrats and glad we were able to help you.