Wide Band Oxygen Sensor

I read an interesting article (by wayno) some months ago. He praises the value of a "wide-band oxygen sensor" when re-jetting your carbs.

I'm trying to find out more on this device (gauge & sensor). It does sound a simple device to check the Air to Fuel ratio through the full range of throttle openings, from idle to "wide open throttle".

Any info would be appreciated, such as, is it worth the investment for a "joe-blow", like me?

RegardZ.

there r some members that use them. OMR and testorosa come to mind. i thing the end result was they can tell u the ratio at a constant throttle position very well but struggle during transition periods. i'm sure they will chime in and correct me soon.

omr also had success using a Gunson color tune for the idle circuit. ask him if he would recommend the gunson over the o2. the gunson is a lot cheaper.
I use my ear. I have purchased a gunson, but never gut around to trying it. :blink:

I have one too. While I havent yet had the opportunity to use it, I can comment. You're right Mark, it will tell you constant position only. So you can get a good idea at a number of different throttle positions at a constant speed, and also test during acceleration as long as you keep your throttle position constant. It'll be really good for me when I get my manual slide carbs since I'll be able to put marks on my grip for throttle position. Should really help with tuning. A lot of people change out main jets but thats only really in effect the last 20% of the opening or even less. So you can really see what part of the carb to change up.

I think Testa said he needed both the Colortune and the wide band to completely adjust the carbs. The reason being that the idle speed adjustments are per carb and the wide band meter only shows you an "aggregate" of all four cylinders.

I think if you get your idle to a good aggregate value and just take a look at your plugs after idling a bit, you'll be able to get it pretty close. I'm not overly concerned about my idle being 100% on, not really gonna damage your engine if she's idling smoothly and has a good O2 reading.

Hey Garn, here's the link to my thread where I explored the use of an Innovate LM-2 wideband data logging system: kzrider.com/forum/3-carburetor/417399-da...g-for-tuning-your-kz

The LM-2 allows you to log multiple inputs onto a flash memory card and it includes software that will allow you to analyze the data at your PC in the safety of your home. I like this feature because it eliminates the human error present when trying to mentally log throttle position vs AFR.

I found it to be a great help when tuning my bike. True, the individual cylinders idle adjustments are individual, but you can still tune them by any method you like and verify that the aggregate yields a desirable AFR. Allow me to clarify Mark's statement about the ability to analyze AFR at transitions. It's not so much that you cannot analyze at the transition as much as it shows the carburetor's in-ability to properly meter fuel in those transitions. One thing that I discovered was that my particular carbs were suffering from worn jet needles/needle jets. That had a profound effect on my ability to tune. Keep in mind that you spend a fair amount of time running on the needle jet circuit.

Anyway, I have since changed to a set of VM29's that are correctly tuned for my bike and since the bike runs fine, I have no reason to continue logging data. That's why I quit posting in that thread. If you decide to purchase a wideband, I would be happy to assist you however I can. By the way, I will probably put mine back into use if I ever get my 1075cc motor put together. I will update as I see fit at that time.

Well, in my opinion it gives a very good reading of dynamic AFR changes, as long as you use an analog gauge to show you the AFR in real time while you're riding.

My bike has simple, mechanical slides, and therefore, the rate at which you open or close the throttle will affect the transitional AFR. You can see the differences in AFR even with minor differences with throttle opening rate. The analog gauge is very reactive.

By watching in real time while riding, you can really get a feel for how the bike is reacting to differences in throttle control.

I have a couple videos that show how fast the needle reacts.



By keeping in mind what you are doing with the throttle and seeing how the bike reacts, you can immediately see if the AFR is going too rich or too lean, and can adjust the carbs accordingly.

The video shows how the bike can run seemingly pretty well even at AFR's as lean as 16:1 and as rich as 10:1. When it's cold and you are decelerating with closed throttle it's at 16:1, but still no backfires or strange effects. However at very light throttle, while the motor is still cold, it definitely feels weak and sluggish when the AFR is around 14 to 15. That's something that's hard to get from only looking at data.

Also, when you do some acceleration runs, you can tell there is tad bit more rush if the AFR only swings down to 10.5 as opposed to 9. Under normal hard acceleration, the needle swings down to about 10.5 or 11, briefly, then jumps back up to 11.5 or 12, then as the gear winds out, it should end up around 13 just before the next shift.

When I get those type of dynamic numbers, that's when the bike feels fastest and smoothest. As the temperature changes, so do the numbers. Hotter weather always registers richer, and vice versa. So really, ideal jetting at 50 degrees won't feel as powerful at 80 degrees. But a good jetting will be smooth and drivable at most temperatures, even if it feels a tic slower at the extremes.

To go along with Testa and Loudhvx...

Truly helps in jetting with out a doubt...

My situation has the added benefit for AZ emissions requirements, yearly!
Helps in jetting where the Gunson came in handy but this is a non load condition, mostly at idle. Yes, there are 3 tests for tests of the throttle twist but not quite the same as on a load (drive)...

Not to mention to what just happened which seems to be pre-detonation of just newly inserted gasoline fill up. The AF/R gauge would have provided me some insight to what was occurring, thus I could have had some pre-warning and lay off the throttle and baby her home....

But oh fucking no was I about to pay attention............... :pinch:






Yeah, I believe this added insurance will be well worth it...

Thanks guys for the replies & links.
Perhaps this Wide-band Oxygen Sensor, may not be the way to go as mine is an accelerating problem, not a constant throttle opening check.

I have a steep sloping drive from garage to roadway and although the engine is warm, idles and revs well, it "peters-out" when I progress about 10 feet up the slope. I can only make it by severely slipping the clutch. No power, I can't say it bogs-down, as that term I associate with too much fuel and I really don't know if that is the case.

Compression is good and timing is correct. Maybe the coils are dying under load?
I had this problem before with another Z1 and never did solve it.

Basis questions... Where does the sensor connect to the carb? How big is the sensor?
RegardZ?

Well, as I said, I use it primarily to check the AFR through acceleration. Then for reference I record the numbers during steady cruise.

If the jetting is correct, then a steep incline will generally produce richer than normal AFR's. This is because the engine is being held back from reaching it's potential RPM by the added load of going up hill.

If your problem is merely a jetting issue, then the o2 sensor would show it.

But if the problem is as pronounced as you say, there might some other issue involved.
The 02 setup is not really a "cheap fix". It's more of a long term investment for jetting more than one vehicle.

I put a cheapo K&N A/F Ratio meter on my turbo bike - welded a bung on the spider pipe right where the 4 pipes come together.

Once the weather is better I'll have a better view of rich / lean conditions that are tough to determine when stationary and until the turbo is fully wound up.

Depending what I find, I may permanently install a better setup.

Garn wrote: Thanks guys for the replies & links.
Perhaps this Wide-band Oxygen Sensor, may not be the way to go as mine is an accelerating problem, not a constant throttle opening check.

I have a steep sloping drive from garage to roadway and although the engine is warm, idles and revs well, it "peters-out" when I progress about 10 feet up the slope. I can only make it by severely slipping the clutch. No power, I can't say it bogs-down, as that term I associate with too much fuel and I really don't know if that is the case.

Compression is good and timing is correct. Maybe the coils are dying under load?
I had this problem before with another Z1 and never did solve it.

Basis questions... Where does the sensor connect to the carb? How big is the sensor?
RegardZ?

I have to wonder if the steepness of the slope is causing the floats to fall down thus giving a temporary rich condition due to the overly high fuel level. Does the bike exhibit the classic signs of richness? Dull exhaust note combined with black smoke from the tailpipes? If it were lean, then you would hear the popping noise associated with a lean condition. Personally, I wouldn't think it should have anthing to do with the coils. I would think that weak coils would show up at high rpms not driveway speed. You should be able to preform the electrical tests in the service manual to rule out the ignition.

By the way, the sensor connects to the tailpipe not the carb. It measures the spent exhaust gases. It is about the size of a spark plug.