Have you ever seen this problem? Linkage issue

[pede69]

This is a bit strange to me...

1978 70hp Johnson Seahorse.

(Strange part at bottom)

Been fighting a low idle issue.

Spits and sputters at low idle.
Compression around 105 in all three.

Replaced 2 coils.
Today just rebuilt all three carbs.

No change.

Well... after firing it up after carb rebuilds,
Nothing had changed.

Dang it... I thought, what the hell can this be?

Well... while engine was running, I decided to pop
out the high speed linkage rod.

Holey crap, engine idled down right and ran fairly
smooth at low RPM idle.

So I shut the engine off, popped the linkage rod back
in and looked into the carbs. One butterfly was
completely closed and two were open just a bit.

With the linkage rod in, the engine will not run right.
With it out, it runs pretty much as it should.

OK... here's my issue.

The linkage rod is hooked up on the top of the two
holes and popped into the little plastic receivers
from the side closest to the carbs. AND THERE IS
NO WAY TO ADJUST IT.

I don't know if I can explain this where you can
understand it.

The only thing I can guess is that someone changed
the linkage. I am including a link to a few pics so you
can see the linkage rod and the carbs.

On a side note, if the lower of the two mounting holes
were used, the linkage would line up perfectly, but
the linkage rod would have to be pushed in the plastic
holes on what I would call the outside. Meaning snapping
them in towards the carbs.

Problem with that is, then the control arm would
hit the rod at half throttle. That won't work.

I can not find a pic of the exact correct linkage. If you
guys can figure out what the heck I am saying from my
jumbled up explanation, please let me know if you have
ran into the issue before and just what the fix is.

Here's the link to the pic's.
http://jaxehost.com/boat/

I need to add one more pic, with the rod in. It will be
there soon.

Thank you all for reading this and for your valuable time,
John

 

[Joe Reeves]

Re: Have you ever seen this problem? Linkage issue

The linkage rod is hooked up on the top of the two holes and popped into the little plastic receivers from the side closest to the carbs. AND THERE IS NO WAY TO ADJUST IT.

Retard the throttle somewhat if needed so that the cam is not touching the throttle cam roller.

Loosen the adjusting screw on the upper and lower carburetor throttle side plate. This will allow all of the butterflies to close. Tighten the adjusting screws.

 

[pede69]

Re: Have you ever seen this problem? Linkage issue

I'm sorry....

I did not make it clear.

The linkage rod that is connected, connects to the rear side. Loosening the screws on the front side will make no difference. The linkage rod IS NOT connected to that part. There is no adjustment to where the linkage rod is connected to. This is visible in the first pic.

This is why I think the linkage may have been changed before I got the boat.

The top and bottom carb that has the adjustment screws has NOTHING connected to the part that moves when the screw is loosened. The cam adjustment you see in the pics is just there while I am messing with it. I know how to set it when needed.

Did you look at the pics?

Thank you for your time,
John

 

[Faztbullet]

Re: Have you ever seen this problem? Linkage issue

Here is what Joe is saying...

 

[pede69]

Re: Have you ever seen this problem? Linkage issue

Thank you Joe and Faztbullit...

I now have two important things to point out.

I can not even remember how many auto engines and auto carbs that
I have rebuilt over the years. And I can not for the life of me figure
out how I have made such a jack *** of myself. I have been highly
mechanically inclined all my life. To overlook such an obvious fix is
beyond my comprehension. Maybe it was just too simple for me.

Second... now I have to take a serious look at my logic abilities
and figure out how the hell this happened. I used to be the guy
that all my friends came to to figure out what they could not.

As you can see, I am kinda upset about this blunder.

Anyway... enough of my personal rambling.

Thank you two guys for your help and patience.

All the best,
John

 

[Joe Reeves]

Re: Have you ever seen this problem? Linkage issue

There are times when it's difficult to see the forest for all the trees in front of it. Happens to all of us from time to time.

 

[samo_ott]

Re: Have you ever seen this problem? Linkage issue

But now the real question. Did it work?

 

[levi_tsk]

Re: Have you ever seen this problem? Linkage issue

im guilty there joe

 

[Fisherball]

Re: Have you ever seen this problem? Linkage issue

pede69, Sounds like it may have been what's called a senior moment! I'm don't know your age but it could be a factor. If you are blond it can be much worse!! I'm quite experienced at having senior moments myself.

 

[Cofe]

Re: Have you ever seen this problem? Linkage issue

pede69, Sounds like it may have been what's called a senior moment! I'm don't know your age but it could be a factor. If you are blond it can be much worse!! I'm quite experienced at having senior moments myself.

Senior moment? and blond too.............Well you haven't really experienced anything until you have achieved being able to hide your own Easter eggs.