electric choke operation

[robeward]

Just purchased a new to me boat. Albemarle 242 express. Has a fairly standard GM 5.7 in it.

Now the part where i fudge up terminology. It is a carbureted version. Maybe they all are. Not the point though. It has an electric choke. It is mounted directly to the carburetor.

I come from the outboard world where you simply push the key in and while it was in the electric choke would squirt some gas every second or so.

this choke is tied to the throttle somehow. at least that is how the seller explained it but he wasn't that great at it. according to him you pull the throttle lever out from its mount (which just keeps engine in neutral) and then make short pumps forward to choke the engine. does this sound correct? is there a certain forward position where the choke makes contact and squirts gas. kinda hard to explain but i bet someone can understand me and point me in the right direction.

 

[Maclin]

Re: electric choke operation

In the automotive world the electric choke means something entirely different.

In the Outboard world the choke is actually activated or (choke plates forced CLOSED) by an electric solenoid. Normal cold position for the plate(s) is wide open.

In the automotive and marine world, when referring to an electric choke for an inboard engine the normal position for the choke plate when cold is CLOSED. There is an electrically powered bi-metal coil with a linkage to the choke plate. When the ignition is on the bi-metal coil heats up and expands and slowly moves the choke plate to eventual wide open position.

If it is a marine Holley carb then the choke plate does not have to be set by moving the throttle, but moving the throttle before cranking during a cold start does squirt in fuel and helps for quicker starts. You may need to leave the throttle open just past idle or a minue or 2 as the engine warms up and the choke plate begins to open.

 

[eavega]

Re: electric choke operation

Assuming this is the same as in my carburated 3.0 L Mercruiser. The electric choke is separate from the accelerator pump. The electric choke is nothing more than a bimetal strip that will close the choke butterfly when the engine is cold. As it warms up the bimetal strip will relax and cause the choke butterfly to open again. The pumping action with the throttle when you disengage the shifter actuates a small pump inside the carb that will get a bit of fuel into the carb throat to aid in starting. Your starting procedure is essentially correct: disengage the shifter, pump throttle 2-3 times, leave throttle 1/3 forward, crank. When the motor starts, adjust throttle to 1500 RPM until warmed up. Move throttle back to neutral to re-engage shifter, cast off.

Rgds
Eric

 

[Bondo]

Re: electric choke operation

Just purchased a new to me boat. Albemarle 242 express. Has a fairly standard GM 5.7 in it.

Now the part where i fudge up terminology. It is a carbureted version. Maybe they all are. Not the point though. It has an electric choke. It is mounted directly to the carburetor.

I come from the outboard world where you simply push the key in and while it was in the electric choke would squirt some gas every second or so.

this choke is tied to the throttle somehow. at least that is how the seller explained it but he wasn't that great at it. according to him you pull the throttle lever out from its mount (which just keeps engine in neutral) and then make short pumps forward to choke the engine. does this sound correct? is there a certain forward position where the choke makes contact and squirts gas. kinda hard to explain but i bet someone can understand me and point me in the right direction.

Ayuh,.... It takes one full stroke of the throttle, to Wot, to set the choke, cold,...

Subsequent strokes richen's, by causin' the accelerator pump to squirt gas,...

 

[robeward]

Re: electric choke operation

this is perfect. exactly what i need. i have basic of carbs but just need to expand it to the current setup. i will get the manufacture of carb later.

so the bimetal strip is the only 'electric' part of this system correct? and it is 'on' when the ignition is on? just for understanding purposes if i accidently cut ignition switch on for a couple minutes before cranking then choking action would not exist because the plate would have warmed up?

should i assume that i have an accelerator pump? sounds like it is a standard item. it is built into the carb itself and is actuated by swift pumps of the throttle correct? i read the description on wikipedia so i think i understand that now.

lastly are there two sets of butterfly valves? one for the electric choke and then a second that actually is the throttle?

 

[robeward]

Re: electric choke operation

while we are at it what is the propper name for this type of throttle system with a carb? I read about TBI and of cource the computer versions with MPI etc.

 

[Bondo]

Re: electric choke operation

while we are at it what is the propper name for this type of throttle system with a carb? I read about TBI and of cource the computer versions with MPI etc.

Ayuh,.... The "Throttle System", is the motor's Induction system,...

Yer's is Carbed,... Carbs come in 1bbl., 2bbl., 'n 4bbl....

Efi is Efi, 'n Mpi is Mpi,... both 'puter driven,...

Yer right in most accounts above, the electric part of the choke, pulls it Off,...

The choke On, comes from throttlin' to Wot, 'n the electric bi-metal coil cold,.....

'n Ya, carbs got accelerate pumps,..

 

[MikDee]

Re: electric choke operation

this is perfect. exactly what i need. i have basic of carbs but just need to expand it to the current setup. i will get the manufacture of carb later.

so the bimetal strip is the only 'electric' part of this system correct? and it is 'on' when the ignition is on? just for understanding purposes if i accidently cut ignition switch on for a couple minutes before cranking then choking action would not exist because the plate would have warmed up?

Yes, & yes again!

should i assume that i have an accelerator pump? sounds like it is a standard item. it is built into the carb itself and is actuated by swift pumps of the throttle correct? i read the description on wikipedia so i think i understand that now.

Yes

lastly are there two sets of butterfly valves? one for the electric choke and then a second that actually is the throttle?

Yes again! If you have an electric choke system, then you have a carburetor. TBI, or any other type of fuel injection, doesn't have a choke, they have an Idle Air Control valve system (IAC)

 

[robeward]

Re: electric choke operation

the carb is an edelbrock.

i assume it is a 4 barrel since i have an 8 cyl

i will being doing some more reading on it.

one more question. do these carbs still have float bowls? do they gum up as easy as 2 stroke outboards since we don't have the oil/fuel mixture going on? How often do you suggest rebuild/cleaning carbs like this?

i know the engine has a manual fuel pump so i need to do a little more learning on that also.

 

[Bondo]

Re: electric choke operation

the carb is an edelbrock.

i assume it is a 4 barrel since i have an 8 cyl

i will being doing some more reading on it.

one more question. do these carbs still have float bowls? do they gum up as easy as 2 stroke outboards since we don't have the oil/fuel mixture going on? How often do you suggest rebuild/cleaning carbs like this?

i know the engine has a manual fuel pump so i need to do a little more learning on that also.

Ayuh,.... Go to Edlebrock's website, then Tech help/ resources,...

In there is a link to a Pdf. that has Everything you'll ever need to know 'bout Yer carb,...

I've got it saved on another 'puter, it's the Bible of Carter AFB Clone carbs,...
Which is the currently available 4bbl. option at Mercruiser,... a Carter Clone,...

 

[robeward]

Re: electric choke operation

Ayuh,.... Go to Edlebrock's website, then Tech help/ resources,...

In there is a link to a Pdf. that has Everything you'll ever need to know 'bout Yer carb,...

I've got it saved on another 'puter, it's the Bible of Carter AFB Clone carbs,...
Which is the currently available 4bbl. option at Mercruiser,... a Carter Clone,...

then that is what i will do. thanks for the tip.

this is going to be an offshore fishing rig for me and my cousin so i want to build as much knowledge as possible. for safety and fun. i feel much better about things now after these few posts.

 

[Bondo]

Re: electric choke operation

then that is what i will do. thanks for the tip.

this is going to be an offshore fishing rig for me and my cousin so i want to build as much knowledge as possible. for safety and fun. i feel much better about things now after these few posts.

Ayuh,.... then if ya haven't, head on up to Don'S Adults Only section at the top of this forum,...

Ton's, 'n Ton's of Great info in there,...

 

[Maclin]

Re: electric choke operation

If this is the AQ271C you have mentioned in other posts I believe the carb would have been a Holley when new, your actual carb may be a transplant, carbs all work the same but linkages and wiring can be different between different brands.

 

[HT32BSX115]

Re: electric choke operation

do they gum up as easy as 2 stroke outboards since we don't have the oil/fuel mixture going on? How often do you suggest rebuild/cleaning carbs like this?

i know the engine has a manual fuel pump so i need to do a little more learning on that also.

In essence, NO. They don't "gum up" like a 2-stroke as long as you keep fresh fuel in them. My last carburetor was pristine clean when I took it apart after 20 years of summer-only (JUNE-SEPT) use. The only damage was my destroying the gaskets taking it apart.

Also, if you only boat in "warm" weather, you may not need to have an operable choke at all.

(I disconnected and wired-open my choke long ago...................... if I need a choke to start my boat up, it's still too cold to go boating!!)

 

[robeward]

Re: electric choke operation

thanks for all the help. ran her myself for the first time last weekend. I pumped throttle a couple times. turned the ignition for three to five seconds (manual fuel pump) pumped a couple more times, and she fired right up