A/F Gauge for tuning

[dynajohn]

I have used a RB Racing A/F gauge in the past for tuning carbs. The RB gauge has been around for a long time. I bought mine in 1998 to tune a set of 39mm Kehin flat slide carbs on a Kawasaki ZX-11. The problem with the RB is it is narrow band and it is not as accurate with the 10% ethanol blend gas we see at the pump these days. The RB gauge (my older one) is calibrated for a lambda of 14.7 and 10% ethanol blend pump gas most of us use has a lambda of 14.2. Narrow band sensors are also only linear over a narrow band of A/F readings.

I ordered a new Innovate MTX-L wide band digital air/fuel gauge to tune the 48 mic carb on my new S&S 124. This is a self contained gauge that has data logging capability that can be used with other Innovate systems as well as 3rd party data loggers. The gauge can be set for different lambda values and fuels unlike most other A/F gauges and the Bosh LSU4.2 wide band sensor it uses is accurate over a wider range of A/F values. I have had excellent results using a Innovate LM2 data logger tuning my 08 corvette and I expect the same quality from this Innovate product.

Some may question why use a A/F digital gauge to tune a carb bike. In my case I have 3 exhaust systems I want to play around with before doing final dyno testing & tuning on this engine. Using an accurate wide band digital A/F gauge takes the guesswork out of tuning each carb circuit and speeds up the process of jetting for each exhaust system. When it gets down to testing the three systems on the dyno I will have good baseline jetting for each system. Saves on dyno time.   

[Y2KRKNG]

Is this a portable unit with a sniffer up the pipe or more permanent using O2 bungs?

[koko3052]

Mine uses O2 bungs but I have made a sniffer for bikes that don't have the bungs

[gordonr]

I have used a RB Racing A/F gauge in the past for tuning carbs. The RB gauge has been around for a long time. I bought mine in 1998 to tune a set of 39mm Kehin flat slide carbs on a Kawasaki ZX-11. The problem with the RB is it is narrow band and it is not as accurate with the 10% ethanol blend gas we see at the pump these days. The RB gauge (my older one) is calibrated for a lambda of 14.7 and 10% ethanol blend pump gas most of us use has a lambda of 14.2. Narrow band sensors are also only linear over a narrow band of A/F readings.

I ordered a new Innovate MTX-L wide band digital air/fuel gauge to tune the 48 mic carb on my new S&S 124. This is a self contained gauge that has data logging capability that can be used with other Innovate systems as well as 3rd party data loggers. The gauge can be set for different lambda values and fuels unlike most other A/F gauges and the Bosh LSU4.2 wide band sensor it uses is accurate over a wider range of A/F values. I have had excellent results using a Innovate LM2 data logger tuning my 08 corvette and I expect the same quality from this Innovate product.

Some may question why use a A/F digital gauge to tune a carb bike. In my case I have 3 exhaust systems I want to play around with before doing final dyno testing & tuning on this engine. Using an accurate wide band digital A/F gauge takes the guesswork out of tuning each carb circuit and speeds up the process of jetting for each exhaust system. When it gets down to testing the three systems on the dyno I will have good baseline jetting for each system. Saves on dyno time.   

Its a great idea. I run a Zietronics unit and hooked up intake and oil temp thru it as well. I run a Lectron carb and did it for the same reasons. Down side is its not water proof I just covered in plastic though.

[dynajohn]

Is this a portable unit with a sniffer up the pipe or more permanent using O2 bungs?

You can use it with either but I use welded in bungs for this kind of application. This is a 52mm (2 1/16") round gauge that I will mount on the left handlebar. I ordered a 52mm gauge cup and handlebar mount. It has three connection cables. One cable with connector is for the Bosh LSU4.2 wide band exhaust sensor. The second cable with connector is a digital serial port I/O for connection to my portable computer for programming or downloading logged data. This gauge comes with Innovate's logworks software for configuring the gauge and data logging. The third cable is a 5 wire lead for connection into the  electrical system but I will only be using 3 of the wires for my purpose. The red wire connects to a ignition switched +12VDC source. The Black wire connects to the negative battery terminal. The white wire connects to a + 12VDC headlight wire which allows the dimmer feature on the gauge to work at night. The other two wires are analog DC outputs which will be capped off. I will make up a 3 wire plug connector for this wire cable so the gauge can be easily removed when not in use for tuning.

You can use a exhaust clamp (innovate part # 3728) to mount the Bosh sensor at the pipe outlet but it is not recommended by Innovate for single or twin cylinder applications because of reversion at the pipe outlet. I weld the exhaust bung (supplied with the unit)  into the front exhaust down pipe within 6 inches of the exhaust flange which is the preferred sensor location.

[x1rider]

I fabricated this sniffer with an old SS piece of tubing I had.  You can use the length of copper tubing you need to get as close to the exhaust port as needed and the coiled piece on the other end prevents fresh air from being sucked in.

[NCTURBOS]

I used this F.A.S.T. dual sensor kit when I was tuning in the S&S "G" carb w/ one t-jet, and it worked great and made vast improvements!  However, I always found myself trying to make the tune even better, when I could/should have just left it alone.

Being able to run two sensor simultaneously and datalog them was the ticket!


K.

[attachment removed after 60 days by system]

[x1rider]

I used this F.A.S.T. dual sensor kit when I was tuning in the S&S "G" carb w/ one t-jet, and it worked great and made vast improvements!  However, I always found myself trying to make the tune even better, when I could/should have just left it alone.

Being able to run two sensor simultaneously and datalog them was the ticket!


K.

I should have gone with 2 sensors, especially with my dual Mikuni/dual intake runner since each cylinder is fed independently.

[turboprop]

I used this F.A.S.T. dual sensor kit when I was tuning in the S&S "G" carb w/ one t-jet, and it worked great and made vast improvements!  However, I always found myself trying to make the tune even better, when I could/should have just left it alone.

Being able to run two sensor simultaneously and datalog them was the ticket!


K.

Does it log RPM along with AFR? Does this unit have inputs for any other sensors?

[dynajohn]

I used this F.A.S.T. dual sensor kit when I was tuning in the S&S "G" carb w/ one t-jet, and it worked great and made vast improvements!  However, I always found myself trying to make the tune even better, when I could/should have just left it alone.

Being able to run two sensor simultaneously and datalog them was the ticket!


K.


I considered getting a dual channel wide band A/F but I couldn't see the advantage when using a single carb and common manifold. Dual channel is necessary for a FI bike where you have individual control over the two injectors. It would be nice to know what the A/F is for each cylinder but what control do you have to affect it if one cylinder is slightly off?? Just trying to learn something here I may not know. 

[NCTURBOS]

Does it log RPM along with AFR? Does this unit have inputs for any other sensors?

There is a separate small module, which I have, that allows it to datalog with RPM.  You can playback the datalog right on the screen of the unit or download the file to your laptop/desktop computer and playback the graph there as well.  It does not have any input for additional sensors.

The dual sensor kit allows you to run just one sensor, dual sensor with dual read-out, or dual sensor with a single read-out average of the sensors.  I was running a boarzilla exhaust that already had o2 bungs in both head-pipes, so I ran the kit with dual sensors/dual read-out.  It allowed me to see the differences between both cylinders simultaneously throughout the entire pull, making sure not to lean out one or the other.  I didn't have access to a dyno so I was making highway pulls in 5th gear to 5k rpm w.o.t., which was enough pucker factor for me! I never really got to tune in the T-jet up to the 6500rpm rev limiter...

Ed...  Mine is sitting in a box in the shop not being used at the moment.  You're more than welcome to play with it if you'd like!  I'll box & ship it, just let me know...

K.

[NCTURBOS]

I considered getting a dual channel wide band A/F but I couldn't see the advantage when using a single carb and common manifold. Dual channel is necessary for a FI bike where you have individual control over the two injectors. It would be nice to know what the A/F is for each cylinder but what control do you have to affect it if one cylinder is slightly off?? Just trying to learn something here I may not know.

I guess for me it was being able to monitor both cylinders simultaneously w/o having to swap the sensor back & forth as I was making jet changes.  If you're real hardcore and start making plenum volume changes, runner size/length changes, rocker ratio changes, etc. or anything to try and equalize the AFR the more important and easier it would be having both cylinders monitored.

K.

[turboprop]

Does it log RPM along with AFR? Does this unit have inputs for any other sensors?

There is a separate small module, which I have, that allows it to datalog with RPM.  You can playback the datalog right on the screen of the unit or download the file to your laptop/desktop computer and playback the graph there as well.  It does not have any input for additional sensors.

The dual sensor kit allows you to run just one sensor, dual sensor with dual read-out, or dual sensor with a single read-out average of the sensors.  I was running a boarzilla exhaust that already had o2 bungs in both head-pipes, so I ran the kit with dual sensors/dual read-out.  It allowed me to see the differences between both cylinders simultaneously throughout the entire pull, making sure not to lean out one or the other.  I didn't have access to a dyno so I was making highway pulls in 5th gear to 5k rpm w.o.t., which was enough pucker factor for me! I never really got to tune in the T-jet up to the 6500rpm rev limiter...

Ed...  Mine is sitting in a box in the shop not being used at the moment.  You're more than welcome to play with it if you'd like!  I'll box & ship it, just let me know...

K.

Good information. I have a Wego III, single channel unit, works well, but always looking for something better. Will keep you offer in mind. Are you going to Cinci this year?

Ed

[mr_natural78]

Great thread. I want to get an A/F guage and was looking at the one from R&B Racing. I have a carbed bike and ran a mik45 but am switching to a mik48 this winter. My heads, new manifold, mik48, and a/c backing plate are all with WFO Larry now. My bike is a 2000 dyna. When I bought my fat cat with bb baffle I bought one for 02-05 dyna instead of one for an older dyna. The mount the exact same. The only difference is the one I bought has bungs for 02 sensors in each head pipe. I wanted that one with the bungs already since I was planning to get an A/F gauge.

[dynajohn]

Great thread. I want to get an A/F guage and was looking at the one from R&B Racing. I have a carbed bike and ran a mik45 but am switching to a mik48 this winter. My heads, new manifold, mik48, and a/c backing plate are all with WFO Larry now. My bike is a 2000 dyna. When I bought my fat cat with bb baffle I bought one for 02-05 dyna instead of one for an older dyna. The mount the exact same. The only difference is the one I bought has bungs for 02 sensors in each head pipe. I wanted that one with the bungs already since I was planning to get an A/F gauge.

I have the RB racing single sensor setup. This is a narrow band A/F sensor that is only linear in accuracy from 14/1 to 15/1 air fuel ratios. Checking RB's website the current price for the single sensor NB meter kit is $295.00. This includes the RB meter, one 1 wire NB sensor and a weld bung. RB now has a dual sensor wide band meter which costs 295.00 but does not include the two wide band sensors or necessary weld bungs. If you get the dual channel RB wide band meter you will need to buy the two WB sensors and weld bungs separately.  Curiously they do not list the Bosch WB sensors in their price list. The two WB sensors and bungs will cost you at least another $120 not including a handlebar mount for the RB meter which they want $49.95 for. I still don't see a compelling reason to use a two input A/F meter to tune a carb bike with a common plenum manifold on a street bike. So if you want a RB narrow band single sensor A/F meter kit you will be out $295 plus $49.95 for the meter mount plus freight. If you want the RB dual channel meter you will be out $295 plus about $120 for the sensors plus $20 for two weld bungs, plus $49.95 for the RB mount plus freight. One other thing to ask RB is what the stoic value the RB meter is calibrated for. I believe the Rb meter is still calibrated for a 14.7/1 stoic value where as the stoic for 10% ethanol gas which most pumps now dispense is 14.2/1. I base this on the RB meter tuning instructions posted on their site. Look around and you will find better values than the RB product these days.

I purchased my Innovate wide band single channel A/F meter on Amazon. The meter which comes with the Bosch WB sensor and a weld bung cost me $159. I purchased a 52mm meter cup from the same site for 29.95 and a handle bar mount for another $15 and the freight was free. This Innovate product has far more capability than the RB product but it does require some setup where the RB product is basically a plug and play product.   

[mr_natural78]

when i first saw this thread i checked out the innovative one and also found it for 159. i looked at a few others people mentioned in the thread. I really like the innovative one. seems like a great deal compared to the prices of the wego, r&b, and the f.a.s.t. products. I think I'll go with the innovative. I just want to be able to get my jetting in the ball park before taking it to my dyno tuner.

[dynajohn]

when i first saw this thread i checked out the innovative one and also found it for 159. i looked at a few others people mentioned in the thread. I really like the innovative one. seems like a great deal compared to the prices of the wego, r&b, and the f.a.s.t. products. I think I'll go with the innovative. I just want to be able to get my jetting in the ball park before taking it to my dyno tuner.

That is my purpose. I have a new S&S 124 with a 48 mic carb and I want to get good baseline jetting for three exhaust systems before putting the bike on the dyno to test which exhaust system works best with this motor. Having good baseline jetting for all three exhaust systems will save me time on the dyno.

The wego WB sensor does not have to be free air calibrated before using it but it is slower according to Innovate Than the Bosch LSU4.2 WB sensor they use. I don't see the calibration procedure as a big deal. On a daily driver you calibrate the Bosch WB sensor before instillation, calibrate again after three months, and thereafter every 6 months or 10,000 miles whichever comes first. Since I am not going to use the WB gauge except to tune I will not have it mounted after I am finished tuning. I will use it again only if I make a change.

[CraigB1960]

I run the Innovate Motorsports 3844 MTX-L Air/fuel unit on my '76 Shovelhead.  I use it to tune and check my S&S Super E.  Works really good. 

[dynaglide]

looking at the MTX-L, it comes with either an 8 ft or a 3 ft sensor cable.  The kit with the 3 ft sensor cable says that the overall length is 4.5 ft.  I need about 4 ft to run from my handlebars to the rear header pipe on my Dyna - does the "overall length" advertised mean it'll fit?  Or do I need to get the longer cable and stow the excess someplace?

[CraigB1960]

looking at the MTX-L, it comes with either an 8 ft or a 3 ft sensor cable.  The kit with the 3 ft sensor cable says that the overall length is 4.5 ft.  I need about 4 ft to run from my handlebars to the rear header pipe on my Dyna - does the "overall length" advertised mean it'll fit?  Or do I need to get the longer cable and stow the excess someplace?

I got the 8' one (10' total) and the sensor went to the front pipe of my FXE.  I had a lot of extra wire, which stowed easily on the down tube and under the console.  If you need 4', than I think you will be pushing it with the shorter cable.

[speedzter]

I ordered a new Innovate MTX-L wide band digital air/fuel gauge to tune the 48 mic carb on my new S&S 124. This is a self contained gauge that has data logging capability   

So the only way to log data with the MTX system is to use an external device like a laptop ?
I think I prefer the LM-2 that will log AFR and RPM to an SD card, you can then set up a scatter graph in
Logworks, which gives a good overview of whats happening.
This is a poor example, as the RPM pickup was playing up, but you get the idea.

[CraigB1960]

I ordered a new Innovate MTX-L wide band digital air/fuel gauge to tune the 48 mic carb on my new S&S 124. This is a self contained gauge that has data logging capability   

So the only way to log data with the MTX system is to use an external device like a laptop ?
I think I prefer the LM-2 that will log AFR and RPM to an SD card, you can then set up a scatter graph in
Logworks, which gives a good overview of whats happening.
This is a poor example, as the RPM pickup was playing up, but you get the idea.

Yep, this is a major limitation for the MTX IMO.  You can use a laptop or their data logger designed to interface to the unit (it is expandable). But for my shovel head and carb tuning, the MTX works perfect.  I'm running an S&S Super E...only got so much you can adjust anyway.

[dynajohn]

I ordered a new Innovate MTX-L wide band digital air/fuel gauge to tune the 48 mic carb on my new S&S 124. This is a self contained gauge that has data logging capability   

So the only way to log data with the MTX system is to use an external device like a laptop ?
I think I prefer the LM-2 that will log AFR and RPM to an SD card, you can then set up a scatter graph in
Logworks, which gives a good overview of whats happening.
This is a poor example, as the RPM pickup was playing up, but you get the idea.

Yep, this is a major limitation for the MTX IMO.  You can use a laptop or their data logger designed to interface to the unit (it is expandable). But for my shovel head and carb tuning, the MTX works perfect.  I'm running an S&S Super E...only got so much you can adjust anyway.

Same here Craig. For fuel injection you need to datalog to tune while riding the bike but I don't need to datalog to tune a carb. Without making some special provision to monitor throttle position you can't log it meaningfully on a carb bike anyway. If you are tuning a F/I bike this gauge alone is not the answer. I would probably use a DJ power vision or any number of similar tuning tools for a HD F/I bike.

I take a piece of 1/2" white masking tape and wrap the throttle grip with it next to inside edge. I then install a wire pointer and make witness marks at 0%, 25%, 50% 100% throttle position. With this done just follow the circuit tuning instructions in the Mick tuning manual using the MTX A/F gauge to set up the idle circuit, pilot circuit, correct needle (4 available) & needle clip position, main jet based on throttle position. Same procedure for a S&S except you have fewer tuning circuits in the carb to work with.

[dynajohn]

looking at the MTX-L, it comes with either an 8 ft or a 3 ft sensor cable.  The kit with the 3 ft sensor cable says that the overall length is 4.5 ft.  I need about 4 ft to run from my handlebars to the rear header pipe on my Dyna - does the "overall length" advertised mean it'll fit?  Or do I need to get the longer cable and stow the excess someplace?

I got the 8' one (10' total) and the sensor went to the front pipe of my FXE.  I had a lot of extra wire, which stowed easily on the down tube and under the console.  If you need 4', than I think you will be pushing it with the shorter cable.

My Innovate MTX meter kit came in today. I purchased the motorsports version with the shorter 36 inch cable. Just for you guys that are thinking about buying the one with the 8 foot cable version, be aware that there is 15" of meter cable that plugs into the 8 foot cable plus the WB sensor has another 28" of cable that plugs into the other end of the 8 foot cable. That's 11 1/2 feet of total cable length. The motorsport version has a 36 inch cable for a total of 69 inches of cabling between the meter head and the WB sensor. If you are going to install the WB sensor in a weld bung on the front pipe or rear pipe the shorter cable version is more than enough.   

[dynaglide]

thanks for the info