Choke questions

"I just replaced my carburetor

"I just replaced my carburetor. It's a 1976 120 Mercruiser with the two barrel carb. (2GC/2GV) The old one had a mechanical automatic choke, the new one has an electric automatic choke. The guy I bought it from said all I had to do was connect the terminal on the choke to the + side of the coil. I looked in the manual and it appeared that he was right, so I did it that way. I also ran a ground wire to the carb and plugged the heat riser from the exhaust manifold because the new carb doesn't use it.

So my questions:

1) When I turned on the ignition, the choke did not close. It's a moderately warm day, so should it have?

(The engine did start.)

2) How does the choke know when to open/close if it just has one positive lead from the ignition switch and no heat riser?

Thanks,

--FatBear"

"the electric choke is set wit

"the electric choke is set with a cold engine.once the key is in the on position, 12v heats the element to open it.you would have to be off for a few hours to see the choke close"

A cold choke won't close u

A cold choke won't close until you actuate the throttle. It closes mechanically and opens electrically.

"So if the choke doesn't c

"So if the choke doesn't close after I have pumped the throttle a couple of times (and even held it open and wiggled the choke linkages) with the engine at roughly 70 degrees (outside air temperature most of the day) does that mean the choke heats up really quickly (less than a minute after turning on the ignition) or is defective or needs adjustment?

Thanks,

--FatBear"

"You bought a used carb? The

"You bought a used carb? The choke may need adjustment or it's worn out; the bi-metal coil that expands and contracts w/heat and cold is pooped out. I replace them at that stage even though they can be adjusted especially if the choke cover has to be moved a few inches from the index points.

Look on the side of the choke cover for 3 screws holding it on. One screw should be grounded. Around the rim of the choke assy. at the 12 O'clock position there should be 3 vertical index marks at 11:55 a.m., 12:00 and 12:05 p.m. Note: they may be located at the 4:00 p.m. position. The choke cover has one mark on it. The cover's index mark should be near the other 3 marks. Initial settings: Left of 12 is lean and right is rich.

On a cold engine @ 70 deg. F. the choke should be nearly closed or closed all but 2/16" to 3/16". To adjust the choke plate position just loosen the three screws and turn the choke cover to the lean setting (left) until it nearly closes as stated above. Tighten the screws. Turn the ignition to RUN and watch the choke; it should begin to open in a few minutes. Feel the choke cover; it should be getting hot to touch. If it doesn't then it's either got a burnt heater, no 12 vdc or a bad ground. Let us know what you find."

Correction:

Initial setting

Correction:

Initial settings for a new choke cover: Set it at 12 to start then move it Left of 12 to make it RICH if the engine spits and sputters and right to make it LEAN if it loads up and belches black smoke.

"It was a "remanufactured&

"It was a "remanufactured" carb. Brand name is Mallory. It looks like they take the basic castings and replace everything else. I decided to go that route because some of my linkage parts were rusty and sticking and the whole thing looked pretty ratty. The price was $250 from a guy on eBay who specializes in carbs. The price for the same item from a marine supply store was over $500. And it did start right up after I got the battery charged.

I would imagine that the bi-metal coil was replaced, too, but I haven't looked inside to confirm it.

Grounding: There was a green-painted screw on the top of the carb. In building construction green screws are ground screws, so I used that to attach my ground wire. Should I move it to one of the choke cover screws as you mentioned?

I will adjust the choke and test as you suggested. It is currently set at 12 but is not closing and the engine is still belching black smoke, so I'll need to adjust the mixture and then let it all cool down before I can do the choke.

Thanks,

--FatBear"

The green paint you touched ju

The green paint you touched just voided your warranty; it tells the mfg. you opened the top of the carb. Move the ground to the choke screw. Put the choke in the freezer 2 mins. or spray the coil w/canned air to chill it. Make sure the end of the coil is contacting the choke butterfly.

"While I was moving the ground

"While I was moving the ground wire to the choke housing I noticed that not only was the choke not closing, but it was floppy-loose. Since I was taking off one of the three screws on the choke adjuster disk I just took the other two off to take a look inside. The choke coil has a little hook on the end which is supposed to engage a lever and rotate the choke shaft. But they were not properly engaged. When I put it back together correctly the choke worked the way it should.

Thanks for the help and advice.

--FatBear"

Brian:

Nice work. Glad you

Brian:

Nice work. Glad you took the initiative to look for the problem; you solved it.

"Not only did he solve it, he

"Not only did he solve it, he posted the fix!!!
It will help the guy behind him with a similair problem.
I believe its important to post a final solution, if there is one.
Chris"

Canned air to work on a choke?

Canned air to work on a choke? That's a fantastic idea! Guy is da man!

If that was the condition of the carb after rebuild I would be a little concerned other problems don't creep up every now and then.