'56 Johnson Javelin set screw broken

[KathyD19]

This restoration project has been one step forward, two steps back the entire time! After troubleshooting electrical problems from starter to motor today and finally getting it running for the first time since hooking up the throttle/shift cables, I tested the throttle at the control box and it goes from completely down (idle) to only straight up (noon) and won't push any further forward. I've had the motor out on the lake using a tiller handle throttle before and I know the motor ran faster than that before (although the tiller handle was very stiff and hard to turn, I kind of had to turn it pretty hard to get it past the mid way point to really go WOT). My boat-guru neighbor had attached the throttle/shift cables up for me and my husband was standing by him watching. He was puzzled that the throttle handle at the control box wouldn't go any further than straight up but he figured (without the motor running) that must be my WOT. So...since I wasn't by the motor when he and my husband attached it, I went inside to ask my husband what he remembers the neighbor doing and why I could only get 1/2 throttle out of the motor. Hubby came outside and I walked to the control box to show him but he didn't follow me, he went right back to the motor and yanked on the idle set screw area (didn't see what he did) and then he said "Oh crap, I think I broke your motor. Oh well, it's old and you've already wasted enough time and money on it." and then then he went back inside. I found the spring in the grass and later found half of the broken set screw in the grass too (the rest of it is still stuck up in it's hole mount.) What do I do now? Do I have to scour ebay or marine junk yards online to find a replacement set screw or are they universal? Can I just use any bolt that is the same size and has threads. Is it easier for me to kill or divorce my husband? I"ve come so far on this project I can't give up now. And any info on why the throttle control won't go up any further would be appreciated too. Thank you.

 

[F_R]

Re: '56 Johnson Javelin set screw broken

In the first place, that plastic idle set screw has nothing in the world to do with only getting half throttle out of it. The purpose of that screw is to adjust how SLOW it goes when the throttle is pulled all the way back.

Secondly, you are going to have to deal with that very stiff throttle control, if you expect to use remotes.

OK, on to the question: There is an interlock bar on the side of the powerhead that limits how much throttle you can give it when it is in neutral or reverse. My guess is the problem is related to that. The interlock may not be pivoting freely, OR more likely it is not going all the way into forward gear.

EDIT: Oh, and the other question, yes you can use any 1/4-20 bolt of the correct length to replace that plastic screw.

 

[KathyD19]

Re: '56 Johnson Javelin set screw broken

Thank you! I'm heading out to work on the old girl now. Any hints as to what the interlock bar looks like or where it is located? I looked on the parts diagram I have and didn't see a part listed by that name.

 

[F_R]

Re: '56 Johnson Javelin set screw broken

I guess they call it a part number 303970 Shifter lock. It is a long flat bar on the starboard side, running from the gearshift, up to the armature plate, pivoting in the middle, spring at the top end.

 

[KathyD19]

Re: '56 Johnson Javelin set screw broken

Got it. I haven't gone out to check it yet but if it's not pivoting freely, what do I do to remedy that? Is it something that needs greased?

 

[HighTrim]

Re: '56 Johnson Javelin set screw broken

Maybe have your husband hold the plug wires next time you are testing for spark, give him a little jolt to straighten him out, lol

Kidding aside, take a pic of the interlock and we should be able to see what is going on.

 

[KathyD19]

Re: '56 Johnson Javelin set screw broken


Here's a picture of it with the shifter in forward. It seems like it does go completely forward. I have other pictures I've taken of it in reverse and neutral if you need to see them.

 

[F_R]

Re: '56 Johnson Javelin set screw broken

Looks fine from what I can see from here. There is a round pin in the shifter handle that rides in the notched track on the shifter lock. It needs to go all the way to the end of the track in forward, which I am assuming it does. At that point the sifter lock is pivoted away from the brass plate on the armature plate, allowing it to rotate all the way toward full throttle.

 

[yorab]

Re: '56 Johnson Javelin set screw broken

Hi KathyD19. I've been following your threads because I've had similar problems before, albeit with a different motor. Therefore, I can't help you too much. However, I would suggest that you pick up a service manual. They really help to explain the function of the various motor systems.

The original factory service manual (FSM) is far and away the best book due to the fact that it is very specific to your motor. However, these manuals usually assume that you have a basic knowledge of the outboard. The aftermarket manuals (Seloc, Clymer, etc) each cover a range of years and only some of the information contained within will relate to your particular model. A strong point of the aftermarkets is that they do a very good job of explaining the fundamentals and they don't assume that you know anything about outboards.

FSMs can be found at the Ken Cook Company (www.outboardbooks.com) and aftermarkets can be found all over the web. Please note that there are strong opinions about the 2 types of service manuals available. This post is my opinion only and specifically relates to experience that I have with manuals that cover a 1963 75hp.

+1 for HighTrim's suggestion that you have the hubby help you out with the spark test

 

[Chinewalker]

Re: '56 Johnson Javelin set screw broken

When you were attempting to throttle up in the driveway, was the shifter handle in forward? The throttle will only move about halfway when the shift is in neutral...

 

[KathyD19]

Re: '56 Johnson Javelin set screw broken

BINGO!!! Chinewalker that was it!!! Works fully at WOT when it's in forward! Thank you everyone for the help!!!!