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Adjusting choke

willxfs

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"I'm working on a 4.3L v6

"I'm working on a 4.3L v6 mercruiser with the vacuum choke set up. Here's a picture.
375029.jpg
choke"">
My problem is in the choke linkage, I think. The butterfly on the carb stays open all the time. As you see it in the picture, when you start the engine the vacuum piston sucks in completely but the linkage arm just slides in the slot. I tried attaching the linkage arm to the single hole and this set up seemed much better. When the engine was not running the choke would completely close. While running the choke would open... but only 1/2 to 2/3 of the way open. There was not enough throw of the linkage arm to completely open the butterfly on the carb. How do you adjust this. Can I just straighten out the linkage arm to gain some more throw. There is a "V" shaped bend in the arm that is hard to see because its painted black - the same as the carb in the background. Thanks"
 
"That part is the choke pull o

"That part is the choke pull off, the choke element itself shoud be on the other side of the carb and should be electric."
 
"With the engine COLD,

remo


"With the engine COLD,

remove throttle cable linkage from carb,
turn carb throttle about half way and release it.

The choke butterfly should slap shut all the way!!

When you start to crank the engine vacuum is produced and the CHOKE PULL OFF that is in the picture should open the butterfly ~ 1/8" no more!! no less!!
To set this remove the vacuum line and put a longer one on it and suck on it untill the vacuum module is completely seated, measure gap of butterfly, if not 1/8 inch BEND link arm SLIGHTLY to get it there.

Reattach original vacuum hose in place.

If you have a electric choke module or a mechanical one with a link going to a bymetal spring on the other side of the carb the adjustment is done there but only when cold.

the side of the carb in the pic is NOT where you need be for your problem.

Please take a pic of the other side and repost.

Either way the choke on the other side is adjusted when cold and is adjusted so when the engine is cold there is enough bymetal spring pressure to close the choke butterfly.

As it warms the bymetal spring expands or contracts and that causes the butterfly to open.

If it is not openning all the way check for mechanical interferences with the butterfly linkage."
 
"Thanks for the replys. I wil

"Thanks for the replys. I will take a picture of the other side tomorrow and post it. The other side has the throttle linkages. The cables you see in the picture are for the starboard motor. You are looking at the port motor in the picture.

This motor is a 1998 and originally had a carb with an electric choke. Sometime ago we thought we had a bad carb and bought a new one. Turned out to be a bad engine and the carb you see in the picture sat in a box for several years. This past summer, a mechanic said he couldn't get the secondaries to open and the carb needed to be rebuilt. I gave him the one you see in the picture to install. Its a weber 4 barrel, just like the old one but doesn't have the electric choke. It has that vacuum thing in the place of the electric choke. I took the electric choke off of the old carb but couldn't install it because the linkage was not quite compatible. I'll get a picture of both the old choke and new (opposite side) tomorrow. Thanks again"
 
"Ayuh,... There should be ano

"Ayuh,... There should be another link/ rod from the single hole in front of the slot, going down to the bi-metal spring mounted in the choke stove of the intake manifold...
It's not on the other side of the carb,...
It's just plain ole Missing...."
 
Also good catch BONDO I have n

Also good catch BONDO I have not looked at one for a while and the pic is a bit disoriented.

None the less without a choke module of some kind the choke butterfly will never open all the way or close all the way propperly. NEVER!!!

You MUST get the correct parts or have the original carb rebiult..............
 
"Ayuh,... It helps that I hap

"Ayuh,... It helps that I happen to have that same carb sittin' on my desk,...
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"
 
"Thanks for the help guys. So

"Thanks for the help guys. So I'm thinking that I will try to get the electric choke to fit instead of trying to round up the missing mechanical choke parts. Assuming that I can get the choke linkage to work my next question is: On the photo below (old carburetor) there is an air passage marked by the red line. On the new carburetor (installed on motor) this air passage is not there. The base of the new carburetor looks exactly like the one in the picture except that the air passageway (red line) had not been drilled out. Is this airflow into the electric choke absolutely necessary? I'm wondering how the electric choke will perform without that air passageway.

375116.jpg
choke
 
"I'm not sure what that ho

"I'm not sure what that hole is, but the elec choke uses 12v to heat up the coil, the thermostatic choke usually has a small "stove" on the intake is on top of the Exhaust riser and heats up and expands the spring and opens the choke."
 
"Between the old school style

"Between the old school style heat stove pipe, and the electric choke i like the old school better.

My friend has the electric on his 93' 3.0, mine is a
85'my choke opens faster, then his.

My motor smooths out faster and i can pull off the dock sooner. It's a matter of only 3-4 minutes difference but to him it seems longer cause i'm already half way out the river. His is a faster boat and he passes me down the way a piece."
 
Is it possible that I dont hav

Is it possible that I dont have a choke stove on the top of the intake manifold. I looked today and didn't see anything. This motor was originally set up with the electric choke. Anyone have a picture or diagram of the choke stove. Thanks
 
"Ayuh,... Ain't got a pic

"Ayuh,... Ain't got a picture handy, But,...
If the manifold has a little pocket, right below the hole by the slot, that's about an inch square or so,...
With a little screw hole next to it,...
You can go buy the stove,+ linkage to fix it...
Or,...
Convert the carb to an electric unit...
I believe Edlebrock sells the "Kit",+ I Know it fits these carbs..."
 
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