Trying to do some preventive stuff. 2001 250 ox66

[Bitesomthing]

I have heard so mush about the O2 sensor on the yamaha outboard that i want to pull mine and check/clean it. i have never done this and am wondering if it is fairly simple to do. If you have any suggestions i would gladly use them.
Thanks
Chris
2001 2502dv ( southern Ca)

 

[Megabyte]

Chris, Do you have reason to believe that your O2 sensor is malfunctioning?

Having asked that, here are a few tips that I gave another 2-stroke owner to extend the life of the O2 sensor and make for a happy motor.

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The best thing you can do for any 2-stroke motor is to feed it clean, water free fuel by using a Racor or Yamaha fuel/water separator.

If your fuel tends to sit for long periods of time, use a fuel stabilizer such as Sta-Bil or Store-n-Start to minimize varnish and fuel breakdown.

The next thing I would suggest is regular use of Ringfree at the rate of 1 oz of Ringfree per 10 gallons of fuel to minimize carbon deposits and fouling.

Regular use of Ringfree is one of the best preventive measures you can take to keep your 2-stroke motor running strong.

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Hope this helps.

 

[TomS]

If your engine is a 2001 and you haven't checked it before, I highly recommend that you take it apart to inspect/clean it. Make sure you also clean out the draw tube that goes between the O2 sensor and the engine block.

Its pretty easy to get to, the O2 sensor itself looks a little bit like a spark plug which is mounted in a metal box that attaches to the side of the engine. I would highly recommend that you loosen the O2 sensor before removing the box from the engine, its a lot easier to remove that way. Once the box is removed, you can pull out the tube that goes into the engine block, unscrew the O2 sensor and take a look.

Use carb cleaner or ring free to help clean off the carbon, but be very careful not to get these liquids above the threads of the O2 sensor.. just use it to clean the bottom half away from where the wires come out.

This is required reading before you dig into the project:

http://www.boatsetup.com/O2sensor.pdf

-- Tom

 

[John_Madison CT]

Like a lot of this stuff, the first time doing it, it seems kinda hard, but after your done, you feel like a pro..

I did my O2 sensor once and it is a fairly simple job. Lots of articles on the web about doing it the hi-tech way, which requires you measure output voltage and such, but if your engine is running OK, I see no reason to do that.

For regular preventative maintenance, cleaning the O2 sensor is probably a good idea once per season, or a a minimum, once ever other depending on hours.

Once I got the sensor out of the cast iron holder (part that attaches to the block), I soaked it first in Ring Free, then some Carb cleaner. Never soak more than the tip. Be sure to also clean the "dogbone" piece that transfers the gasses from the block to the sensor.