Anyone know what this is on my flame arrestor?

[Ctmangrum]

This isn't a vacuum advance is it?

[bud37]

Nope....looks like electric choke...

[g36]

Yes that's a electric choke

[Ctmangrum]

Thanks

[km1125]

Yep, definitely electrically-operated choke mechanism.

Looks like someone added a ground wire, so there may have been issues in the past with how it was working.

That's the nice type that is adjustable (loosen three screws and pivot the cap). There's a little mark on the top to see where it's set at currently. Looks like the main (+) connection could use some cleaning up to make sure it has a good electrical connection.

They are easy to test. On a COLD engine, make sure the choke is shutting completely (you may need to bump the throttles on some to allow the choke to reset). Once it's closed completely, you can just hook up a 12V source right to that connection on the side and watch for the choke butterfly to open. Within 5 minutes (there's actually a spec somewhere, but 5 min is reasonable), it should go from "fully closed" to "fully open" position. You can adjust the cap if the choke doesn't close all the way or if it was closed too much (which causes it way to long to open, or not open all the way).

I can't see it on that carb, but on most there's also a "choke pulloff" that's operated by vacuum. Once the engine starts, this "choke pulloff" will pop the choke open just about 1/8-3/16" to see enough air in to run.

[km1125]

What's also interesting in that pic, is that the flame arrestor originally had a second hose attachment. This would have been for the vent for the other valve cover. Either that hose is missing, or this flame arrestor wasn't original to the engine and they just removed the superfluous attachment.

flame_arrestor2.jpg

[Ctmangrum]

Im guessing its not the original since the other engine has the same type arrestor. Im asking about the vacuum since I am converting to Electronic ignition and it makes a difference on what part I buy. Didn't see one on the distributor but, this caught my eye. Thanks.

[bud37]

QR_BBPOST . Im asking about the vacuum since I am converting to Electronic ignition and it makes a difference on what part I buy.

Try to be sure to buy marine specific parts, electronic ignition and distributor both.....there will be no vac advance on marine engines.
I think I noticed the line from the PCV from the other valve cover going to the base of the carb, just at the back of the pic....if that is the case there will be only one hose to the flame arrester.

[Ctmangrum]

Yea, did what research I could and found the right HEI but, then started doubting when I saw that part. Time to get to work.....when it finally cools down.