Newly Rebuilt Carb Bogging, WHY?

Posted By: MaxHeadroom

Newly Rebuilt Carb Bogging, WHY? - 08/09/13 11:11 PM

I picked up the correct carb for my car, Carter AVS off ebay. Seller said carb ran good, but needs accelerator pump. Since I plan to rebuild the whole thing anyway, picked it up. Got it, took apart, cleaned, and rebuilt with all parts from the rebuild kit. No real issues I found, except on float not adjusted right. Accelerator pump did not look too bad either.

Put it on the car, primed it and started well, warmed up, then took it out. If I hit it, it bogs to almost stalling, recovers and runs good then. Have to feather the gas otherwise does the same. Guess this is the problem the previous owner had with it and figured it needed the acc pump, which I would have thought so too, but it still has the problem.

What am I missing? Have rebuilt several Carters in the past, never this type of problem. Car ran fine with old incorrect carb.

Any ideas?

Posted By: MaxHeadroom

Re: Newly Rebuilt Carb Bogging, WHY? - 08/09/13 11:33 PM

Quote:

your secondaries are coming in too fast. tighten up the back secondaries. I had the same problem, loosen screw and tighten it up. problem solved, change out your accelerator pump too if your getting dribbles out of your squirter.it should shoot out nicely

I put in a new accelerator pump from the kit. What do you mean tighten up the secondaries. Loosen what? This is an original Carter AVS, not the new ones.

Posted By: 70AARcuda

Re: Newly Rebuilt Carb Bogging, WHY? - 08/10/13 12:13 AM

does the accelerator pump squirt gas as soon as you move the throttle blade?

Posted By: JAKE68

Re: Newly Rebuilt Carb Bogging, WHY? - 08/10/13 01:24 AM

On a avs there secondary air valve spring is adjustable. Tighten up till bog goes away.

Posted By: 383man

Re: Newly Rebuilt Carb Bogging, WHY? - 08/10/13 01:46 AM

Quote:

On a avs there secondary air valve spring is adjustable. Tighten up till bog goes away.

As he said there is a spring that controls the tightness of the secondary air valve which is the valve at the top of the secondaries that looks like another choke. If its to loose it comes open to soon before the fuel is coming from the secondary metering system. You can tighten the spring tension to delay the secondary air valve opening to overcome the bog if thats causing your problem. Ron

Posted By: MaxHeadroom

Re: Newly Rebuilt Carb Bogging, WHY? - 08/10/13 02:11 PM

Quote:

does the accelerator pump squirt gas as soon as you move the throttle blade?

Didn't check that, just assumed, but will today, thanks.

Posted By: MaxHeadroom

Re: Newly Rebuilt Carb Bogging, WHY? - 08/10/13 02:12 PM

Quote:

On a avs there secondary air valve spring is adjustable. Tighten up till bog goes away.

Thanks, will give that a shot today, never worked on an AVS, just the AFB type.

Posted By: MaxHeadroom

Re: Newly Rebuilt Carb Bogging, WHY? - 08/10/13 02:15 PM

Quote:

Quote:

On a avs there secondary air valve spring is adjustable. Tighten up till bog goes away.

As he said there is a spring that controls the tightness of the secondary air valve which is the valve at the top of the secondaries that looks like another choke. If its to loose it comes open to soon before the fuel is coming from the secondary metering system. You can tighten the spring tension to delay the secondary air valve opening to overcome the bog if thats causing your problem. Ron

Thank you, will give that a try today, this is the first AVS I have worked on, all the others have been AFB's and there is no need for that. I have been reading up and it say maybe the spring is worn, not sure if you can buy them or what. Hopefully an adjustment will work.

Posted By: CHAPPER

Re: Newly Rebuilt Carb Bogging, WHY? - 08/10/13 09:56 PM

Haven't worked on any AVS carbs for years. When I did, I found a big problem with the accelarator pumps that were made of leather. They would kind of turn 'inside-out' sometimes when they would get dry in the bore. The pump material would stick to the sides of the well and when moved the plunger would move, but the pump would flip up so it didn't push any fuel. Maybe they are making the pump bellows out of better material now...