Tell me about "Wide Band Air Fuel Ratio"

[prayers1 153]

I smell raw fuel a lot and have adjusted my transition slot on the secondaries to .20 thousandths, then I adjusted the mixture screws to it's highest vac which is around 12.5. on my 735 Vac sec. Quickfuel carb

However, I go around the carb starting on the driverside. It seems when I get to my highest vac, nothing changes from a 1/2 turn lean or rich. Also, by the time I get the motor warmed up and adjust the right rear screw it gets way too hot to hold the screw driver to adjust. I'm thinking an A/F gauge will let me know when I reach the highest point instead of running around, reading a vac gauge. Also, I already checked for any vac leaks, there are none.

[j69302 11]

Vacuum gauge is much more accurate for adjust idle mixture. Have you tried a pair of TIG welding gloves? or just mechanic gloves in general?

 

Buying a system with a O2 sensor is a lot of money to accomplish what you are wanting to do. But, you can always use to to tune the entire carb not just the idle.

 

For what its worth, I have mine dialed in pretty good, and it still wreaks like fuel at idle. Even if I lean it out to where is runs rough, it still stinks.

 

Higher vacuum indicates higher efficiency at idle. It will give you much better idea of what is going on then a O2 sensor at idle.

 

Also if you are going to use a O2 sensor to tune the whole carb, you will need a vacuum gauge to do it correctly anyways... It really does make it a lot easier. Many things in a carb or vacuum triggered, even double pumpers have vacuum operated power valves. These need to be timed to your engine.

[stangme428 33]

prayers1 - sorry if i missed it.. but what headers do you have? also, what heads? i have aluminum Cleveland heads and sanderson shorty headers ceramic coated... just curious about how much heat you have.

[1969_Mach1 333]

The motor runs 180*, but I have the 4 corner mixture screw set up. Because of the Export Brace being in the way of the right rear adjustment and the heat from the headers and intake, I can only keep my hand there for a few seconds after the motor is fully warmed up.

 

 

I understand. I also run a four corner idle mixture screw setup. Its on a Holly DP, but can still take time to get them adjusted and the export brace doesn't help. Although my motor runs a bit cooler and I don't have the burning heat issue. On the positive side, after you get them adjusted, you will know how far to back them off of seat and future readjustments are simple.

[prayers1 153]

I have the iron 4V 63cc heads w/sanderson shorties NOT coated.

 

It's not like my hands are catching on fire, but after a while trying to fine tune, the right rear mixture screw is a little tough and the export brace doesn't help either.

I can try a welders glove.

[Alan_Mac 48]

I stopped using ethanol gas because it idled differently with different gas. I use pure gas and it idles and runs the same all the time. I will never put ethanol gas in my Mach1 again. I use(d) an Innovate WB to tune my carb, and it works great. No need to go back and fuss with the carb since my gas is stable. A window fan blowing on the engine would help when you tune.

[1969_Mach1 333]

I have the iron 4V 63cc heads w/sanderson shorties NOT coated.

 

It's not like my hands are catching on fire, but after a while trying to fine tune, the right rear mixture screw is a little tough and the export brace doesn't help either.

I can try a welders glove.

 

 

I was going to suggest wearing gloves but thought maybe you had already tried. Hardware stores usually have an insulated glove that is thinner and less cumbersome than welders gloves. It won't take much. The uncoated headers are certainly not helping. Like another member suggested, a simple house fan in front of the car to move some air across the engine compartment will make a big difference.

[prayers1 153]

What do you guys think about the FAST A/F Ratio Meter kit w/ Dual sensors.

 

This is a kit that you can plug into a laptop.