OX66 O2 Sensor question (another)

[carolinaflare]

Hey Guys, I hate to beat a dead horse and start YET ANOTHER OX66 o2 sensor thread. Ive searched high and low for more recent discussions on the matter but it seems they are all old and not very complete.

I am considering replacing my O2 sensor on my 2000 SX250TXRY ox66 engine.
The previous owner had the enigine running on premix for approx 4 years and NEVER cleaned the OEM o2. I personally have cleaned it 4 times in 3 months.
NOW, with that being said, I have finally finished re assembly of my oil injection system, (tank, pump drive, Floats (THAT WORK), (SW2 on old float was bad, guess he cldnt figure that one out and began premixing.)

I have replaced nearly everything on the engine, LP Fuel pumps (2 were bad), VST filter/clean tank, sent injectors to Dale "fuel injector man", Link and sync, calibration of TPS, New knock sensor (old was rusted and wire fell off).

The point is, im about sure my o2 sensor is going or gone. I HAVE NOT TESTED YET, This is simply a "what if" type of post. Im positive that 4 years of premix with no cleaning, plus me cleaning 4+ times cannot be good for the OEM I have. (which BTW HAS a NGK symbol stamped on it)

NTK-21006 O2 sensor?????????? Anyone using one? RECENTLY? And one hear of blown P-heads possibly linked to it?

Just looking for input. sorry for the additional post , yes i have searched.

thanks a ton
tyler

[rodbolt17]

cleaning WITHOUT testing is kinda like showering with a raincoat.

[carolinaflare]

Rodbolt,
Thanks for the reply. I just now did test and re clean my o2 sensor. I did the bench flame test, it pasted per the service bulletin instructions. It responded to the flame rather quickly, always staying above .5/.6 sometimes .7 when in the flame, and dropping rapidly when out.
The main reason I was asking about the NTk sensor was because I would really like to keep a spare onboard just in case. We do a lot of long offshore trips to the Bahamas, only 55 miles from home port but parts are non existent.

[rodbolt17]

the flame test is equivalent to a teat on a tom cat.
maybe a teat on a boar hog.
your motor do as you wish.

however it CAN pop a piston.

[carolinaflare]

So???? Your saying the ngk replacement sensor is a no go , or saying simply that a bad o2 sensor can lean a motor and blow it. Or both???? How else should an o2 sensor be tested if not per the Yamaha tsb that I had to search to the ends of the ether to find?

You said a non tested sensor is useless and then replied that my test was useless. Ok???? Is this not the purpose of this forum? Or are we all here to make jokes about farm animals?


Not to be a smart a$$ but I'm working on an OX
Not a tom cat , or a boarhog.

[rodbolt17]

do you realize there are about 4 TSB's concerning testing the O2 sensor output?
the only one that DOES NOT work correctly is the flame test one.
yes the O2 sensor can pop a piston.
the ECU is rather stupid yet will react to the O2 sensor output voltage.

the ECU isn't looking is the voltage scaling its simply looks at the voltage and trims fuel accordingly.

you can clean it till the cows come home,self milk and leave.
however if its NOT feeding back the correct voltage its no good.

the ECU does NOT monitor the O2 sensor for any faults or failures.