HELP!!!! Mercursier 2 bbl reasembly

[apollo5646]

Hi all
I really did it this time. I decided to take the Rochester 2 bbl off my 4.3l mercrusier to give it a good cleaning. I took it apart (upper half lower half) what i didn't do was make a note of how the throttle linkage we put together. I got the accelerator pump linkage in the right spot a and working right but I can't figure out how the choke linkage and idle cam go back on. I can get them in the right spot but can't figure out what is supposed to make them move when i move the throttle arm as to simulate the way it would move in the boat. The choke butterfly's just stay closed even though the main one are fully open. Please Help! If someone has a close up of their card that i could look at that would be great or if some one could point me to a rebuild directions with drawings or picture that would work to. Please help



John

 

[Alpheus]

Re: HELP!!!! Mercursier 2 bbl reasembly

Use the Google machine. Lots and lots of pics on there...

 

[Bt Doctur]

Re: HELP!!!! Mercursier 2 bbl reasembly

http://www.boatfix.com/merc/Techbk/94/94hg5b.pdf

 

[apollo5646]

Re: HELP!!!! Mercursier 2 bbl reasembly

I'm confussed does the throttle lever move the idle cam? When i put it together like the picture shows i can move the throttle lever and the pump pumps but the choke stays closed and the idle cam doesn't move am i missing something?

 

[EddiePetty]

Re: HELP!!!! Mercursier 2 bbl reasembly

I'm confussed does the throttle lever move the idle cam? When i put it together like the picture shows i can move the throttle lever and the pump pumps but the choke stays closed and the idle cam doesn't move am i missing something?

....I believe what your're missing is the fact that with the carb in your hand, it thinks it's cold!!! The Choke spring will be tensioned and thus closing the choke butterfly and raising the idle cam. As the choke warms, the spring looses tension and the choke butterfly opens and lowers the cam.

 

[apollo5646]

Re: HELP!!!! Mercursier 2 bbl reasembly

So it would be safe to say that they should operate independt of the other. or to say that moving the throttle has no effect on the choke position?

 

[EddiePetty]

Re: HELP!!!! Mercursier 2 bbl reasembly

So it would be safe to say that they should operate independt of the other. or to say that moving the throttle has no effect on the choke position?

....holding it in your hand: correct.

 

[apollo5646]

Re: HELP!!!! Mercursier 2 bbl reasembly

Does this look right?

 

[boltonranger]

Re: HELP!!!! Mercursier 2 bbl reasembly

Apollo let me pass on an experience I had when I rebuilt mine.
The big flat screw that holds the linkage on - - After I rebuilt my carb it backed out on the water. It fell n the engine but I could not see it and had to get creative to get back to port.
My advice - a drop of blue threadlocker.
-br

 

[dbkerley]

Re: HELP!!!! Mercursier 2 bbl reasembly

I had a very informative post all typed in and my phone decided to reboot. Long story short - find the correct section in the adults only area and get everything bench set to spec and then go remount. The idle and throttle linkages are almost two separate systems. I'm not a tech. I have built alot of carbs.

 

[apollo5646]

Re: HELP!!!! Mercursier 2 bbl reasembly

That a good idea with the lock tite i was thinking along the same lines too... I guess in my minds eye it seemed that if the throttle butterfly's were full open at wide open throttle that the choke would have to be too

 

[EddiePetty]

Re: HELP!!!! Mercursier 2 bbl reasembly

Does this look right?
View attachment 68930

...with the choke cold (and thus closed with the cam all the way up) and the throttle butterflies closed: the picture appears to be correct!