Loose throttle linkage on '66 Johnson

[kfa4303]

Hi all. So after a couple weeks of effort and TONS of help from here at iboats, I got my old 1966 33 hp running like a champ (in the tank any way). Can't wait to get her on the water and get everything set up just right. The only problem is that the throttle linkage from the tiller drive to the motor does not work properly. The gears and teeth don't quite sync up. The main problem is where two little gears merge at the hinge on the tiller. I can twist the throttle and get the gears to interlock a bit, but then they fall out of sync again :/ Is there any way to rebuild/adjust the rods and gears so that they will all interlock and interact correctly? Thanks for all the help forums.

 

[oldcatamount]

Re: Loose throttle linkage on '66 Johnson

I think you may need to put on your "McGyver" hat and do a little experimenting with washers/spacers and that sort of approach. I don't think the throttle rod is threaded and adjustable. Chances are, that something may be bent or just plain worn out and you may need to be creative to cure the problem. Maybe I'm wrong here and someone will jump in with some pointers! Good luck with the project!

 

[FHB]

Re: Loose throttle linkage on '66 Johnson

I have a 57 that had the same problem.

There is a brass shaft running through the tiller and at the end is a gear that articulates with a gear at the end of the verticle shaft that connects to a armature on the magneto. Both gears were worn down. Also there is a plastic pin that runs through the base of the verticle arm that goes in two slots on that verticle gear.Mine was broken and there was alot of slop in the assembly.

Dismantle and clean everything and see what is worn. You may need to replace that pin (Laing outboards). Put the brass rod back in the tiller arm and then put a thin washer on before replacing the gear that goes on that arm. This will push the conical gear up to a part that is less worn. Put fresh litihium grease on all the moving parts.

You may need to look at the synchronization after you do that. If there is slip in the gearing the throttle/magneto do not work as designed.Nothing I did improved my motor's performance more than installing that silly washer.

Frank

 

[kfa4303]

Re: Loose throttle linkage on '66 Johnson

I'll give it a try. Speaking of synchronization, I've never done that and I'm not exactly sure what it is from a conceptual stand point. I have the owners manual form my motor and it explains how to synchronize everything, but the directions are a bit hard to understand. I'd appreciate any info you have about how/why/what synchronizing is all about. Just got the motor running after a few years of it sitting idle so I'm like to get everything set up just right. Thanks for the suggestions.

 

[oldcatamount]

Re: Loose throttle linkage on '66 Johnson

It's called a "link and synch" adjustment. Above the carb, You'll see a small round rubber roller that is attached to a piece of linkage to the carb. That roller, rolls against the "cam" which is part of the timing plate. On the cam, there is a small "hash" mark (or maybe two marks close together). The rubber roller will follow the cam as you twist the throttle handle toward "fast". When the roller reaches the hash mark, that's excatly the time when the throttle butterfly will begin to open. If it doesn't, you need to adjust the linkage to make it happen precisely at that moment when the roller gets to the mark/s. A small off-set mirror will let you see inside the barrel of the carb and determine when the butterfly starts to open. Or, you can make a "special tool" with a small alligator clip and a short piece of wire sticking up. Clamp the alligator clip to the butterfly shaft (on the outside of the carb)and that will give you an exterior indicator of when the butterfly opens. This adjustment has to be as accurate as you can get it. It'll take a couple of tries to get it right.