Monitoring fuel/air mixture - O2 Sensor?
 

With all of this rejetting, airbox and exhaust mods, it may be difficult to determine if we have obtained the proper fuel/air mixture for our particular environment (altitude).

In the past, I have done this analysis by interpreting the spark plug deposits (or lack thereof). I have found this to be difficult to do over the full throttle range. There must be a better way.

I've seen that this can be monitored (not sure exactly how) during a dyno run, but not everyone has ready access to one of these machines.

What about using an O2 sensor and meter? I've read the Nobrakes has installed a O2 sensor, but searched and did not find any details.

What about this device from K&N?

http://www.knpowersports.com/airfuelmonitors.htm

The cheapest that I have found it is from here:

http://www.4filters.com/AirFuel-Rati..._p_6-1745.html

Exactly where would the weld-on fitting be located?

Thanks.

Dan

RE: Monitoring fuel/air mixture - O2 Sensor?
 

Im sure brian will be chiming in on this one..... been there done that.....

RE: Monitoring fuel/air mixture - O2 Sensor?
 

I used a Bosch universal 4-wire O2 sensor. Two wires are connected to 12V and GND for the heating element, one wire is GND, and the other wire is the Signal. The signal wire produces a voltage and the normal range is 0 to 1V with stoichiometric being at around 0.45V. Optimal for this sensor is around 0.90 to 0.92 V. Here's a photo of my setup:

http://nobrakes.smugmug.com/photos/123182508-L.jpg

http://nobrakes.smugmug.com/photos/122921690-L.jpg

http://video.google.com/videoplay?do...97445163401854

The big box up front there is basically just a glorified voltmeter. It's temporary and I just had it on long enough to run some mixture tests. I no longer have it installed. When you remove the sensor, you just plug up the fitting with a screw in plug.

The K&N looks to be about the same setup.

Mine helped me a great deal to verify and confirm my jetting changes.

RE: Monitoring fuel/air mixture - O2 Sensor?
 

I took the easy way and had the dealer rejet on their o2 machine when I had the 300 kit installed.

RE: Monitoring fuel/air mixture - O2 Sensor?
 

Nobrakes,

How did you decide where to have the fitting welded? Is there some recommended min/max distance from the exhaust port? ...or does it matter?

Dan

RE: Monitoring fuel/air mixture - O2 Sensor?
 

Wow Nobreaks! what are all those toggle switches? Do you have a NOS kit?:)

RE: Monitoring fuel/air mixture - O2 Sensor?
 

With the type of dyno you dealerprobably using, the only thingit reallyverifies is that your main jet is dialed-in properly. That's a really good starting point though, because you always want to make sure your main is dialed-in properly before youmess with anything else.

The rest is done by actually riding the bike to see how it feels. In that way, you can pick-up on things like mid-range sputter or surge under a load. If the dealer did all of his measurements inside the garage with an O2 machine, he hasn't done a complete check. Not saying he didn't take it for a spin, but..... Furthermore, if he used only an O2 machinewithout dyno, he hasn't checked much at all very accurately....except for possibly your pilot circuit.

That's where Nobrakes' method can net you better results if you can get steady state readings at different throttle openings...say a long uphill grade.

RE: Monitoring fuel/air mixture - O2 Sensor?
 

If you have the money, get the LM-1 wideband air/fuel ratio meter. It will record your air-fuel ratio, TPS and RPM while you run.

http://www.innovatemotorsports.com/products/lm1.php

http://www.innovatemotorsports.com/images/LM1_Kit_3.jpg

RE: Monitoring fuel/air mixture - O2 Sensor?
 

It needs to be fairly far up on the headpipe - I think the higher the temperature the better on the sensors and with no chance of any air from the silencer disturbing the results. I chose the location on my to coincide with where the Muzzy header expands and it is still a good ways from the mid-pipe joint.

RE: Monitoring fuel/air mixture - O2 Sensor?
 

Nothing quite so sexy. The left switch is the rocket laucher and the right switch is the self destruct which is only to be used as a last resort if it looks like I'm going to be captured as we wouldn't want this amazing piece of equipment fall into enemy hands.