Home made o2 sensor harness?

[magnoman]

Is there a way to test the voltage of the O2 sensor with out buying the yamaha one. I remember seeing a post on a home made one but can not find it.

 

[vx225mota]

Re: Home made o2 sensor harness?

yes, just push your meter probes into the back of the 02 sensor plug where the 02 sensor wires plug into the motor. One pair are for the heater and will read well above 1 volt... 12 maybe.

The other between 0 and 1 volt.

When you've found the correct wires you could buy suitable plugs or splice but the proper harness is cheap so why.

Pushing in the back will get you out of a bind

 

[rodbolt]

Re: Home made o2 sensor harness?

in a pinch paper clips slid up the wire works. the heater is the blue connector and the o2 sensor is black/gray. your looking for .35-.6V and rapidly changing. all tests must be done with the gearcase fully submerged and the engine at operating temps or its usless.
look for the three tech bullitens on how to test O2 sensor output voltage. disregard the bench test using a propane tourch as its usless.

 

[magnoman]

Re: Home made o2 sensor harness?

Thanks so much for your help going to test the o2 sensor know let you know what I find.....

Phil

 

[magnoman]

Re: Home made o2 sensor harness?

Did the votage test on the O2 sensor it seems Ok, sometimes voltage when up to .7 ? I coverd the air bleed hole on top cyl throttle plate and it did make the voltage change.

When I pulled of the air silencer there seems to be a lot of oil draining out of where one of the hoses attach is that normal even looks like it was dripping out onto the engine housing. is that normal.

I also pulled off the plug wires one at a time while idling cylinders #3 & #5 the two lower one when looking at the motor from the throttle plates
do not seem to be sparking nor changing the rpm of the motor....are those the cylinders that become not in use at low rpm?

maybe i should do a comp test/