Topic: oxygen sensors

[Serge]

Have someone tried to install the oxygen sensors into exhaust pipes to set the mixture? I found a gauge in Autozone for $30 and I thought if I buy 4 sensors, drill the holes in pipes and hook them up to the gauge it might be a cheap and fast solution to adjust the carbs for actual running conditions.  Any thoughts on this ? -serge

[Gordon]

Sounds like way more trouble to me than just doing a plug chop, plus you'll end up with holes in your exhaust pipes. 

[Serge]

yeah, I know, I know, about troubles - I guess most of us here do not mind them otherwise we would ride something newer wrt to holes - I meant to have it as a permanent setup with extra gauge ..  just to know if it runs lean before it seized up (who needs spedo anyway ...  My previous time sink 240d 1974 diesel Mercedes seized the engine from overheating so I might overconsern with this now.. of course clearances in diesel engine and air-cooled motorcycle quite different, but still...

[MRieck]

I have my exhaust tapped for an O2 sensor. You need a wideband unit like the Dynojet piece for it to be really useful.

[Serge]

MRieck, thank you for the reply, I knew someone must have taken advantage of new technology to make old bikes run better  !!
do you use one sensor for all cylinders or 4 of them? what brands of sensor/gauge are you using? did you have the housing welded into exhaust and in what place ?  - thanks - serge

[Robert]

I' curious on that too.

I found a install instructions of the "Dynojet Wide Band Commander" here: http://www.racimex.de/content/de/motorrad/dynojet/einbauanleitung.pdf

It's in German, but the pics should give an idea
 
The sensor used with that set is a Bosch LSU4 (Lambda resp. air/fuel ratio sensor).
They recommend to place the sensor ~30 inches behind the exhaust outlet port, also it is said that the sensor should be placed in a 2' or 10 o'clock position to prevent damage to the sensor due to condensed water.

In theorie you would need only one sensor if there's no need for constant monitoring, but for optimal results you'd go for one sensor port per cylinder mounted before any collector as you would otherwise measure only the average air/fuel ratio of two or more cylinder (if one is too lean and the other is rich...)
In theorie (no practical experiences).
 

[OldBoy]

I thought of this some time ago but never got round to trying it out.
You would only need one sensor placed before the silencer/muffler.

As it needs to be at more than 300 degrees C you will probably need the type with a built in heater like the one on Suzuki's SV1000 when placed this far from the exhaust port.

These sensors will only work over a narrow band of air to fuel ratio about 14.7:1 when all fuel is burnt with no oxygen left over. I think a slightly richer mixture is used during acceleration and full throttle for max power.

These links may be of interest.
http://www.markvanderkwaak.com/dbbp/tech-tips/mm.html
http://scirocco.dyndns.org/tech/misc/afgauge/af.html
http://www.dalhems.com/electronics/halmeter.html
http://www.techedge.com.au/vehicle/wbo2/default.htm

A search for O2 sensor or lambda sensor should get some hits.

[cben750f0]

just a thought on this subject... had anyone actually price these lamba sensors... from what i can gather they are gonna cost me more than a rough running bike... to get 4...if i am wrong just say some... but...

[Robert]

It depends where you get them (doh). As lambda sensors are nowadays a mass product (used for emission control with catalytic converters), it shouldn't be theoretically that pricey.
The naked sensor is maybe 30 bucks or less, but then again, I haven't looked into it enough to know if the sensor can be/ has to be modified (housing, cabling). A prefitted sensor that goes straight in into a bundled weld on thread insert for special use in a bike pipe will surely set you back several Pesos more.

[eldar]

$30 for a sensor, 120 over all PLUS cost for a reader. I think I will stick with reading my plugs and syncing.
It may take longer but then I am not racing and if I was, I would not use a classic bike.

I dont mean to be harsh but these are old street bikes and while can still deliver good power, unless you spring for a full electronic ignition and new coils and what have you, add this cost on and you almost have a NEW bike.

[Robert]

It's not for everyone for sure  cost-benefit analysis is propably also a desaster, but that's propably another thread (not limited to O2 sensors in classic bikes  )
Find it interesting though.

[Serge]

Hi Robert,

If you went through with Oxygen sensors installation - please, share the experience !!
I was looking on the other options like colortune plug ($60 + adapter) to set the mixture but I thought that if I find the place to weld in the ports for sensors in the exhaust for reasonable $$ I can as well get a single sensor and reader for the same price and see how it will work ... 

Cheers, - Serge

[Clyde]

Mike, Could you give us some details about your sensor?
How do you use it and how useful is it?
In one of the classic magazines they recommended using a dyno and a sensor to fine tune old bikes.
In Australia here it is getting more difficult to use plug readings with newer fuels such as unleaded, high density and low sulphur fuels. They do not give the same readings as older leaded fuels

[Terry in Australia]

I've got one, a technician mate built a digital meter for me and I plugged the sensor into the collector on my 4 into 1 on my Suzuki GS1000s, my carbs were synched first so the individual readings weren't a major problem, and i found it useful for optimising the mixture. Individual sensors would be better, but I just wanted a "ball park" figure when I installed a "Dynojet" kit. Cheers, Terry.  

[Terry in Australia]

Here's some pics! Cheers, Terry.