Forum

[Creaky45]

Before I launch into a long boring post, has anyone had experience of connecting an O2 sensor on a 500 iron barrel Bullet or any bike for that matter. If so then I can tell you mt problem.

[Creaky45]

Usually check for typos. (I mean my post)

[papasmurf]

Is this any help:-

[Rattlebattle]

Did any iron barrel RE have EFI? Why do you want to install an O2 sensor? Many, including me, remove them....

[Creaky45]

Rattle, Sorry. Mis-understanding. I am only putting the sensor on as a temporary measure and it has a digital display on the handlebars so I can see the mixture when I am riding. When I get it right I will remove it, plug the hole using the plug supplied with the adapter. I just drilled out the existing hole in the engine pipe which used to have a pipe going to ???? and was blocked off anyway and welded in the adaptor. It is still a standard iron barrel with a Mikuni V32 carb. Hope that explains it better.

[Rattlebattle]

Creaky45, thanks for explaining that; I was a bit mystified. So basically you have some sort of O2 sensor reader that will detect how much oxgen is in the exhaust gases so you can then adjust the jetting etc on your carb? I didn't know such things exist but I wonder if you could be so kind as to advise me what it is you have? (I have an EFI bike that I have converted to carb fuelling. It would be handy to do what you are attempting, as I already have the boss in the exhaut header that I have plugged. I suppose a Carbtune would be easier, but less technically interesting). I may have misunderstood; if so please ignore my request.

[Creaky45]

Rattle, That's right. I borrowed this from a mechanic friend and it is normally used on a car. It has 4 wires but I only connect 1 as 2 are for the heater and I guess the last is to go to an ecu. However my friend told me I only need to connect one wire to the display which is on the handlebars. The display has 2 wires for pos and neg. I'm now thinking that because I don't have the heater wires connected it is not getting hot enough to give me a true reading as it reads rich no matter how I jet the carby. I have now got the bike running fairly well and the plug looks good but the display still tells me I am too rich. I will post some photos if I can figure out how. The display is really only a voltmeter reading from 0 to 1 volt using green, orange and red leds. The higher the voltage generated by the sensor in the engine pipe the leaner the mixture. Red is lean and green is rich. I will give you more info if you want. Just let me know.

[Rattlebattle]

Thanks Creaky45. Out of interest I've had a look at the w/shop manual for my EFI C5. The operating range is up to 16v, but no information is given as to what the reading should be at stoichmetric ratio, the ratio of air to fuel that the ECU tries to maintain as optimum. Note that this is for emissions purposes; the optimum ratio for power is around 13:1 rather than stoichmetric which is 14.7 air to fuel (AFR). Not sure how that affects the kit you have but just beware that you might end up with a perfect setting for emissions, not power! You are probably right about the false reading without the heater, apparently the RE EFI ECU runs a fixed ratio AFR until the O2 sensor has heated up sufficiently. Hope that helps.

[papasmurf]

Some years ago, I had a car breakdown in Brittany which required a full exhaust system replacement including catalytic converter. I was surprised that unlike the UK where it is just a fit and drive away job, a complete gas analysis had to be carried out with the engine at full operating temperature.
(Wires attached to the car engine and a probe up the silencer.)
Then a certificate was issued which was valid for two years.

[Creaky45]

Thanks Rattle and Papa, You blokes know more about this stuff than me and on the strength of your comments I think I will just go back to checking the plug and doing a few plug chops. I have just changed from a Mikcarb to a Mikuni V32 and the bike goes much better. But you never know if it is going at its best and I thought the O2 sensor would be the answer but maybe not eh!