Tuning AVS...Chryco style

[kawahonda]

@Chryco

Hi guys,

Please help me wrap this up today. Got a lean stumble off a start. No other running issues.

Chryco mentioned that the float settings are best at 3/8". I wanted to verify this. Right now, my floats are set to 7/32". 7/32" and 3/8" is a big difference. If I move it to 3/8", it seems like I would be going leaner? Larger the clearance, the less fuel will be in the bowl. Seems like I'd want to leave my float height alone @ 7/32".

I'm also going to pull my pump nozzle and figure out what size it is and go one step up.

[kawahonda]

Looks like my pump nozzle is .033-.035". That seems pretty middle of the road....and I'm starting to think that's probably correct. I do have a .043 I could use...

My accelerator pump is in the middle notch.

Please advise what I should do.

Problem: From stop, if I punch the gas, or even just push the gas a little aggressively under load, there is hesitation. Sounds lean, not a rich hesitation. Then it "picks" up. No other running/performance issues.

[Fastmark]

I had my original 70 AVS restored by a reputable guy and it had the off idle stumble. It finally lost all of its acc pump shot. I had a newer better acc pump so I changed it out. It helped considerably but still had a little slow pumpshot. I pulled the top off and notice it has a brass check valve that fills the acc pump well. It was letting a little bit of gas go back in the bowl before it would go to the acc pump. I changed that out with another used one I had and it cured my problem. The next oem AVS I built for a customer, I used a kit from Mikes Carburetor. The kit was very high quality. That carb works great and has a great pump shot. 

[kawahonda]

Solved it. The .043" nozzle was the answer.

Now I'm learning how easy it is to spin the tires with 3.73.

That nozzle upgrade was the single best drivability and performance upgrade I have done to date.

[70 Challenger Lover]

I would try the arm setting first to give a more aggressive shot of fuel. Then try the larger nozzle. These are easy changes and easy to change back. I'd try one, change it back, then the other, change it back and if needed, try both.

I'm not sure on the AVS but could too high a float level cause the gas to spill over inside and slightly flood? Perhaps that is why Chrys suggested a larger gap...just guessing of course.

[70 Challenger Lover]

Good deal!

[Chryco Psycho]

yeh you don't want to move the float down , you could have gone to 3/16 "
The squirter would be the second change I would make after tweaking the pump arm position so you did well .
I am glad the tire spin more easily now !!

[kawahonda]

Still have pump arm in middle position. Haven't touched. In retrospect it may have made sense to try that first.

Either way, it runs perfect now. It just GOES.

As always make sure ignition is perfect before messing with carb

[Chryco Psycho]

I am happy it works better 

[kawahonda]

Now, another 250 miles before I get to drain the rear end and refill....then STOMP on it....

250 grueling more miles.....it takes forever with my driving habits.

[Chryco Psycho]

Looks great , love the bumble bee stripe

[gzig5]

250 grueling more miles.....it takes forever with my driving habits.

Easily solved.  Just pick a town 125 miles away, get in and go.  Two hours there and two back and you are done.  Leave at 8am be home for lunch.   

[kawahonda]

Crycho, do you have any tips for air door adjustment? I just set it per the factory specs....something like 2.5 or 3.5 turns. I forgot which it was (but wrote it down).

[RUNCHARGER]

I loosen the door 1/2 turn at a time until it bogs when I hit it, then I tighten it 1/4 turn until it doesn't bog.

[kawahonda]

Best way is to keep it in 2nd gear and just punch it at 3000 RPM? Does it have to be WOT in order to detect the bog?