dodgem880

Hello

I believe there is something wrong with the linkage controlled bowl vent on my 2245 carb. The vent stem appears to have too much spring tension to allow the weight of the arm to push it down while off idle.

From what I understand the bowl should only vent at idle and this current condition will result in poor gas mileage, correct?

I can easily push the stem down with my finger. I'm not sure what to do about this.

dodgem880

I took my bowl vent spring out for pictures (Pic 1 and Pic 2). I found a company online that sales a replacement spring (Part # 66-100) but, I don't think that will fix the problem. I measured mine and it seem to be similar to whats in their catalog (Pic 3)

My spring measurement
ID .5
diameter .013
length .517
4 turns/coils

(Picture 4) The adjustment page shows the early and late bowl vent setup. The early version with the seal mounted on the arm I understand, that makes sense.

The late version I don't get, I look at that and think "How does that work?, That won't work." How is that arm going to push the stem down with it's weight if there is a spring holding the stem up?

What am I missing? How is this suppose to work?

The only way this seemly could work (that I can see) is if the tang was placed under the vent arm but, I can't find anything pictures of other carbs depicting this and there is a ball point on the top for the tang to ride on.

I know it's a long shot even asking about this model carburetor. As I know most peoples interaction with it is seeing how far they can chuck it.

RacerHog

Not sure.... Mine has an open vent and just goes down to the cole canister. But Mine is a 1977 Truck model.
You might have to check the spring to see which way it works.

RacerHog

LOL... Beat me too it, Posting.... Looks like adjusting the tab will close it off idle...

dodgem880

Thanks for the reply.

I'll double check the spring, but I'm pretty sure it was installed like in the attached picture.

So, that would make the vent normally open.

The tang is adjusted with the throttle resting on the hot idle screw so that the arm isn't touch the stem. When the throttle comes off idle, the accelerator pump bracket moves up allow the arm to fall on the stem... which I assume should push the stem thus closing the bowl vent. I agree thats what the adjustment should do.

Put since the arm itself isn't heavy enough to over come the vent spring, the arm just sits there. Which is why I'm confused I don't see how this thing ever worked.

Perhaps there is something else at play, like the arm is an assist and something else closes the vent like vacuum or heat but, I'm skeptical about that.

If no other ideas come up I guess I'll just adjust it and not question how it works. To be honest I originally didn't have that arm on there since I didn't think it matter as long as the vent was open but, I recently found a post that suggested that letting the vent stay open all the time will affect gas mileage but, I don't know if thats true or not.

RacerHog

Dans a good dude.. But all that vent does is go to the Smog canister. The float bowl is still vented. So effecting fuel mileage, I don't think so much, Emissions might be another story.

dodgem880

Dan seems real knowledgeable. I've never talked to him but, I first ran a cross him and the slantsix forum while researching hei modifications.

But, Thanks, I'll put the spring back and adjust the tang and leave it be. This truck doesn't even have a canister to connect the vent port to.