Using O2 sensor to adjust pilot screws and jets(main jet, needle jet, needle).

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DreamV4

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I am not suggesting this way, let us say, I am writing this for fun.
Some people use this way to adjust fuel. I used it for one of my Harleys.
1.Buy O2 sensor bungs and plugs.
2.Weld them to exhaust pipes about 2" (?) from cylinder head.
3.Install narrow band (I used narrow band) O2 sensor, connect heater wires to battery, voltmeter to signal wire.
4.Find 0.45V screw position, then turn it out 1/4 turn.
5.Remove sensor, install plug.
 

one2dmax

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The factory used a lot further along the pipe to set with but they used a little different then simple O2's. PLEASE NOTE, the stock front pipes are double walled so doing this method is a bit more complicated then is mentioned.
 

aikidoka

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I have bungs in all of my pipes. I used a wideband to get as close to 14.7 as I could then turned a bit leaner later. I since realized I had too large a spark gap for the COPS system. Fixed that now and haven't gone back to check the O2. Bike has been running great this year though.
 

DreamV4

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I have bungs in all of my pipes. I used a wideband to get as close to 14.7 as I could then turned a bit leaner later. I since realized I had too large a spark gap for the COPS system. Fixed that now and haven't gone back to check the O2. Bike has been running great this year though.
From now on you are officially the smartest guy of the forum (with Fire medic). 👍
 

Zu1

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Indeed it is clever way to set the screws. However, if one have good ears, then screws can be adjusted in old traditional way and that too works fine.
Thanks for the info though.
 

maleko89

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I do it by ear. With two of my Vmaxes, it liked it best when slightly richer than 14.7. This assumes the a/f reading on the Topeka dyno was accurrate.

Mark
 

DreamV4

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Indeed it is clever way to set the screws. However, if one have good ears, then screws can be adjusted in old traditional way and that too works fine.
Thanks for the info though.
Probably tachometer can be "ear"
 

one2dmax

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Idle can be lean but for best power and torque you want around 13:1 under load (hard acceleration)
 

aikidoka

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Idle can be lean but for best power and torque you want around 13:1 under load (hard acceleration)
I got my bike from Garrett here on the forum and he dyno tuned it. I didn't measure the screws correctly when I took the carbs apart it clean due to rust in the tank. Never could get it right after that. Turns out cops installed pushed a pin out so three cylinders. By then I had decided to do wideband. After that got plug Gap right.
 

DreamV4

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I got my bike from Garrett here on the forum and he dyno tuned it. I didn't measure the screws correctly when I took the carbs apart it clean due to rust in the tank. Never could get it right after that. Turns out cops installed pushed a pin out so three cylinders. By then I had decided to do wideband. After that got plug Gap right.
Pleeeeese, post link or description/ diagram of your wideband set up, I want to be smart too!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! :)
BTW, I adjusted fuel map of Harley, using O2 sensor, 2 voltmeters and camera, attached to my chest (not a smart way, but it worked fine)
 

aikidoka

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Pleeeeese, post link or description/ diagram of your wideband set up, I want to be smart too!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! :)
BTW, I adjusted fuel map of Harley, using O2 sensor, 2 voltmeters and camera, attached to my chest (not a smart way, but it worked fine)
Bungs were already in the aftermarket headers when I got it. I used this

Innovate Motorsports 3806 LM-2 Digital Air/Fuel Ratio Wideband Meter (1 O2 Sensor) and OBD-II Scan Tool Amazon.com: Innovate Motorsports 3806 LM-2 Digital Air/Fuel Ratio Wideband Meter (1 O2 Sensor) and OBD-II Scan Tool : Automotive
 

DreamV4

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Thanks for the link, but narrow band set up is around $30 (20 new sensor, 6 bung and plug, some wires).
I just need to find out how wide band sensor works, $3 used one.
 

one2dmax

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Good wide band 02 sensors are not $3. If they are it's probably not any good. It may read but will not likely be good readings. I do have an LM 2 around here if anyone needs to borrow/rent it. I need to figure out a cost for the sending unit or just let each person buy their own but use the data logger for no charge except postage there and back.
 

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