So I need a new choke right?

[projo198]

On my 2.3 OMC.

Had more issues on the lake this weekend. Boat was extremely cold blooded, but I could eventually get it started if I covered the carb intake with my hands until it warmed up. It ran fine once it was warm.

I got it home tonight and discovered that the carb flaps were staying wide open when I first start the motor.

Is it correct that the electronic choke below chokes the carb (closes the flap) during start up until the motor warms up, at which point the vacuum plunger that is attached to the same actuator lever opens the flaps when the motor is at running temperature?

Last question; I tested the choke by applying 12v directly to the choke where the alternator usually powers it, and nothing happened. This means it is in fact bad, right?

 

[Howard Sterndrive]

Re: So I need a new choke right?

It could be faulty, or just need adjustment.
That type of choke doesn't respond to engine temp, it opens when IT warms up, not the engine. There's an electric coil inside that heats up as power is applied to it over time. Your choke should be closed with no power. About 2 to 4 minutes of 12V should open it.

I'm not familiar with that particular unit, but if you loosen those 3 screws, I bet you can rotate the plastic part of the housing to add or subtract tension on the spring inside. The manual will say which way is biased more closed.

 

[projo198]

Re: So I need a new choke right?

Ok. I have had it apart in the past, though I am not sure if I reinstalled it correctly.

Does the coil inside the electronic choke EXPAND or CONTRACT as it warms up? With the motor at rest (cold) should there be tension on that coil or should it be free? My carb flap stays wide open all the time, there is no spring or anything that holds them closed until they are made to open by mechanical means. Am I missing a spring or something that would keep them closed? What exactly does the vacuum assembly with the slotted arm do that is also connected the carb?

Bear in mind I have never seen this carb in the correct configuration, it came to me this way. It could be totally missing parts.

 

[gm280]

Re: So I need a new choke right?

Ok. I have had it apart in the past, though I am not sure if I reinstalled it correctly.

Does the coil inside the electronic choke EXPAND or CONTRACT as it warms up? With the motor at rest (cold) should there be tension on that coil or should it be free? My carb flap stays wide open all the time, there is no spring or anything that holds them closed until they are made to open by mechanical means. Am I missing a spring or something that would keep them closed? What exactly does the vacuum assembly with the slotted arm do that is also connected the carb?

Bear in mind I have never seen this carb in the correct configuration, it came to me this way. It could be totally missing parts.

If you apply 12volts to the terminal (and of course ground) and leave it on for about 5 minutes you should be able to feel it warm. If not, then time for a new one. If it does then it was misadjusted on your engine. The three screws should be loosened and adjust the housing while installed on the carb for the choke butterfly to be close before starting the engine from a cold engine. So if you reinstall it, turn the housing (after loosening the three screws) until the choke butterfly just closes. Then retighten the three screws. That is the initial setting for a COLD engine start. They used those type chokes on a lot of older cars in their days... Holley carbs may still use them too... There were about three versions of those type chokes used. One like you have that heats up via 12 volt heater circuit inside the choke housing, a divorced type that heated up via the intake manifold with a tube running up to the choke to supply the heat, and one that used the exhaust heat to disengage...

 

[projo198]

Re: So I need a new choke right?

Ok I see. I think I have the arm of that inner coil on the wrong side of the arm it touches to manipulate the actuator on the outside.

The end of the coil is flared out and "hooked" (see picture below). I assumed the little arm went INSIDE of this hook, as there were wear marks on the brackets holding the cover on that indicated it had been put together in that position.

Now I am thinking that arm goes on the OTHER side of that hook so there should be constant pressure on the coil holding the carb flap closed and the coil releases pressure as it warms up allowing the arm to move up and open the carb flap.

Does this sound correct? If so then it has been wrong for a long time.

 

[projo198]

Re: So I need a new choke right?

Ok, I'm really at loss here. My electronic choke opens the flap on my carburetor. The vacuum assembly connected to my carb also opens the flap on my carburetor. But there is NOTHING that actually CLOSES the flap on my carburetor so that I can start it when the motor is cold. It just sits there. Wide open.

 

[bruceb58]

Re: So I need a new choke right?

When the electric coil is closed(cold) it will be wound fairly tight. That is what holds the choke closed. When you apply power, the coil will unwind as the metal expands which then opens the choke.

You need to adjust the choke closed when the choke coil is cold. i always leave it so the choke plate doesn't quite close all the way. Usually, you need slightly less than fully closed.

 

[projo198]

Re: So I need a new choke right?

ok gotcha. The coil inside move actually contracts instead of expanding like I thought it did. So basically as it expands it released pressure on the actuator arm and allows the vacuum assembly to pull the flap open.

Still idles rough, but I think I'm getting closer. Better than the carb being wide open the whole time.