Mercruiser 260 350v8 choke spring? Different clocked positions

sdowney717

Petty Officer 1st Class
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Jul 16, 2011
Messages
242
I see a lot of potential ones to buy.
They can have the rod eyelet clocked all over the place, which one is right one to get?
Carb is the Quadrajet, and the attaching screw rusted and snapped that holds choke thermostat on the intake.
Has to be drilled and tapped, anyone done this?
example 1
NOS GM Part # 3989060 1970 Corvette 454 1971 Corvette Chevrolet 350 Choke Therm | eBay
example 2
Carburetor Choke Thermostat Walker Products 102-1002 | eBay
example 3
Carburetor Choke Thermostat Standard CV204 | eBay
example 4
71464A01 Mercruiser Marine Choke Thermostat Rochester Carburetors w /Stove Choke | eBay
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Jul 23, 2011
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51,557
Boats don't need a choke if you live where the temperature is consistent within a 30 degree window year round

However yes, the electric choke conversion is fairly inexpensive
 

alldodge

Moderator
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Messages
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I wouldn't worry about which one to use because the choke rod is how it's adjusted.

Use a center punch and make sure it's dead center, drill slow and you bit should be smaller than threads. This way you might be able to re-tap it. Use heat to help drilling. Best method is remove the manifold and take to a machine shop because they know how to do it

So far as switching to electric choke, look for a choke for your model Q-jet and make sure it has all the items to remove old and install new
 

Lou C

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Nov 10, 2002
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13,516
There is an electric choke kit, I think Mike's Carburators and others sold them, keep in mind you want a 12V source that's powered only when the engine is running, if it is powered when you switch on the ignition the choke will come off too soon. Also, an electric choke is more properly called an electric un-choke, because if it's not powered constantly it will close and your mixture will be way too rich.
Those old style divorced chokes do work but on a boat the issue is this, they were designed for cars that ran at 195-200*, not 140 or 160. So they tend to open way slower than an electric. I've had one all these years with this boat (23 years) and what I have found is this, in order to get it to open when the engine warms up (in my case 160*) you have to set it leaner than you would in a car, so that means it won't close all the way with a cold engine. But, if the engine is in good tune it doesn't matter. Set like that, I have found these old-style chokes to work well enough. Personally, I'd like full manual control of the choke, because the beginning and end of our boating season can be cold ( 45-50*) but haven't found one with a long enough cable yet, lol!
 

sdowney717

Petty Officer 1st Class
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Jul 16, 2011
Messages
242
I also have a 1970 Eggharbor which used to have 4GC carbs with manual choke cables. They were really long hard red plastic outside with a steel copper plated hard pull-push wire and chrome knobs. When I went to 4MV Quads, It then had electric chokes. I was happy to go with automatic chokes and newer style carbs. Those manual cables were like 8 to 10 feet long or so.
 

sdowney717

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Jul 16, 2011
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242
have drilled out bigger bolts and tapped new or repaired existing threads with taps on larger sizes. This one is pretty small. I suppose may have been 8-24 originally. May end up a #10 screw.
Just have to see how it works out. I also think a SS screw and antiseize should be used

Would drilling a hole and JB weld gluing in a SS rod from a long bolt work?
That stuff is supposedly good for high heat
 

sdowney717

Petty Officer 1st Class
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Jul 16, 2011
Messages
242
I repaired the shape of the spring, and it works. With heat it moves up. when cools moves back into this position, and that position matches the other Mercruiser part pics online.

1760791631130.png
 

Lou C

Supreme Mariner
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Nov 10, 2002
Messages
13,516
Simple and it works! Just make sure it opens all the way up. I found that when I tried a 140* stat, my engine took forever to warm up so I went back to the 160* I have always used even in salt water.
 
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