O2 Sensor cleaning pics

[bass4cache]

So I tackled the o2 sensor clean out on my 2002 250 ox66 last night. I bought this boat less than a year ago. It has roughly 200 hours on it. The guy I bought it from ran only Yamalube but never ran any ringfree. I couldn't believe how much Carbon build up there was. I had to scrape it out it was stuck so bad inside the o2 sensor holder. And the sniffer tube was just as bad.
I see now why Yamaha recommends the ringfree. Still need to test it out but I think this little bit of maintenance should help alot.
Thanks BBC members!

[stratos195]

That is a whole lot of carbon. I cleaned mine out about a month ago and it was dirty but not even close to that. It made a huge difference on the performance of the boat at take off and idle.

[cbe0001]

I need to do this very same thing to my motor!! Was it difficult?

[bass4cache]

not at all, for instructions, check out the sticky at the top of this forum.

[blownbayou]

super easy.... mine was not too bad.

[JOHN202]

When i had my Ox-66, i used Quick Silver oil and Seafoam and it kept the sensor alot cleaner and i did not have to clean it much at all in the five years i had the motor.

[kyle31]

Mine was just as bad when I cleaned it a year or so ago. I've since quit using yamalube and it's stayed clean.

Here's the sniffer tube. The carbon was so hard I had to drill it out. (sorry so big)

[1999skeeterzx202]

what would a dirty o2 sensor cause to happen

[JOHN202]

what would a dirty o2 sensor cause to happen

Plain and simple, motor would run like crap!, sput and spidder like a plug wire was loose.

[1999skeeterzx202]

Mine sounds like it's sneezing and loading up. Could that be the problem?

[bass4cache]

I had to drill the tube too. I am definately changing oil after I saw mine. Most likely switch to a synthetic or synth blend.

[HaulinBass]

Mine sounds like it's sneezing and loading up. Could that be the problem?

Possibly lean condition, clean O2 sensor, also may need synch and link then TPS adjustment.