Mercarb Choke issue

[tom03]

Hi,

I have a 1992 Merc. 5,0l V8 with a 2bbl Mercarb.

The problem is that the choke flap is always open when the engine is cold.
In order for the flap to be closed I would have to turn the choke cover counterclockwise about 90 degress way off the marks so that the spring within the choke closes the choke flap.

Is this normal ?

regards, Tom

 

[Don S]

Re: Mercarb Choke issue

It may not work any more. Turn it till the choke closes, start the engine and see if it opens after a few minutes.

 

[Bondo]

Re: Mercarb Choke issue

The problem is that the choke flap is always open when the engine is cold.

Ayuh,... Are ya advancin' the throttle to Wot to set the choke,..??

 

[tom03]

Re: Mercarb Choke issue

Hi,
When I do WOT the choke flap wont move at all.
I only get the flap to close when I turn the choke cover counterclockwise so that the index mark points to about 9 o clock which is way off the normal setting.

However the choke coil seems to work . With ignitiom on the choke gets hot and the coil opens the choke flap .
The only thing that worries me is that the choke adjustment is way off the regular setting...

Take care Tom

 

[tom03]

Re: Mercarb Choke issue

hi, anyone out there who could help ?
Choke flap wont open when engine ist cold ,also when throttel in WOT...

 

[jimbo_jwc]

Re: Mercarb Choke issue

Mine had measured dia. of opening when cold and when energiz. It would rotate open . fixed adj was between 10 and 2 . 3.0L Mercruiser Carb

 

[mpdive]

Re: Mercarb Choke issue

I would think your choke coil is bad and the thermostatic spring has lost tension. Replace it with a new spring cap and reset it. Verify choke is energized with a test light when you start it up. Im assuming it's electric assist.

 

[90stingray]

Re: Mercarb Choke issue

Just a thought... I just disconnected mine electrically and wired her open. No need for a choke when its 60 plus degrees ambient air temps. That way it eliminates another possible point of failure, which could leave you not boating.

 

[mpdive]

Re: Mercarb Choke issue

At the danger of being wrong here, If I am not mistaken, there is no choke fast idle cams or pulloffs on these marine carbs. Mostly for safety purposes since the boat could be put in gear while on a fast idle cam. My stock carb is purely dependent on coil thermostatic pressure for opening and closing and is not directly tied to any throttle linkages. It is the operators responsibility to run the engine at a faster idle speed during warm up. If his choke is wide open on a cold engine, then it is either way out of adjustment or the coil has lost it's ability to close the choke. Choke setting are so dependent on the environment you live in and can no way be set with index marks. I alway's advise people to turn the coil just till the plate closes and back off 1 notch. There should be such minimum pressure on the plate that blowing hard on the opening side should move it. I have always set mine this way and have never had a problem. Just my 2 cents worth and I don't mind being corrected if wrong.

 

[mpdive]

Re: Mercarb Choke issue

Hi,

I have a 1992 Merc. 5,0l V8 with a 2bbl Mercarb.

The problem is that the choke flap is always open when the engine is cold.
In order for the flap to be closed I would have to turn the choke cover counterclockwise about 90 degress way off the marks so that the spring within the choke closes the choke flap.

Is this normal ?

regards, Tom

I meant to add that if your are that far off the index marks, it's indicative of the coil losing it's tension. Only other explanation would be that someone took the coil off at one time and has it installed incorrectly on the choke tang.