Johnson 55HP Idle Screw Not Returning in Neutral!

[jasondainter]

I have a Johnson 55hp SeaHorse from 1979.

Please see the video below i took today:

The idle screw as you can see does not return to its stop. I've linked and synced as best I can with this old thing, but this last bit is beating me.

When i push it manually it idles fine and everything else looks to be working as it should be, at WOT the butterflies are straight open, its just when I return back to idle/neutral the throttle cable doesnt seem to push it far enough back.

As I see it adjustment wise I can

1) Adjust the trunnion adjustment nut but as you can see i've done this and its already maxed out (this in itself is a bit suspicious?) so wont go any further.

2) Adjust the "throttle cam yolk" but I'm not convinced that this will really push the idle part back enough and by adjusting this I get all the cam markers etc messed up (which causes me other problems at WOT etc).

I recently took off the entire throttle arm, spring, washers etc and cleaned it all out and re-lubricated using gear oil hoping that would fix but it didnt help.

I'm suspecting the throttle cable is stretched and worn? Its the original one I think probably never changed (from 1979!) so this would seem a likely culprit.

Any other ideas or anyone experienced who can confirm my thinking?

 

[racerone]

Wrong video!!

 

[jasondainter]

Wrong video!!

Oops sorry!
its this video I meant (cant seem to edit original post):

 

[jimmbo]

How long have you had this boat and motor?

 

[jasondainter]

How long have you had this boat and motor?

Ive had it a few years but the boat and motor is from 1979 so pretty old. I'm pretty sure the throttle cables have never been swapped out (they are OMC ones and think theyre original).

I'm considering opening up the remote control box - I got a tip that you can adjust the length of the cable there (its already screwed in the maximum as you see in the video via the trunnion adjustment plastic screw).

Failing that I have a feeling a new cable might fix it I guess it makes sense to get both cables.

Any ideas how I go about knowing how long my cable it bar taking it out and measuring it? And If thats necessary, do you know where I measure from and to in order to get the right length measurement?

 

[jimmbo]

Sometimes the Length of the Cables are labeled on the Cable itself, or are part of the part #. However you might end up taking the cable out to find it. But if you are going to replace them, they have to come out anyway. You could measure the distance from the box, to the Transom, then from the side of the boat to where they cables enter the engine, then it is a matter of adding a certain bit of extra, which is the hard part. OMC used to have a guide in their accessory book

 

[racerone]

On earlier control boxes you could do a bit of adjusting.------Even replace the inner cable.-----Used to do it myself.-----Had someone drive 3 hrs ( happy to find the part ) one way to pick up a piece for these earlier control boxes.-----Newer boxes had what they called " snap-in cables " were quick easy and a time saver.-----No fitting / adjustment to do.

 

[jasondainter]

Thanks both this is extremely helpful.

Jimmbo noted, then ill look for the part number else will take the thing out and measure it the manual way otherwise.

Racerone, thanks for clarifying that I'd heard mixed opinions on whether you could adjust inside the box so thats good to hear. Mine is a 1979 55HP don't suppose you know if that fits into old or new? Otherwise I'll take it apart soon and I guess it'll be obvious if it has something thats adjustable in there.

 

[racerone]

At some point you have to dig in to find the problem.----Guessing does not work.

 

[jasondainter]

OK thanks for help.

 

[Dave1027]

You need to have somebody operate the throttle while you look at the cable and the linkage to see what is binding. It does not help to have the motor running while you troubleshoot this issue.