Sensor cleaning might keep one in tool box
Here you go I wrote this up the first time I did mine.
Someone asked how this was done so I thought I would write it up while it was fresh.
Actually it was easy to remove and reassemble. It took longer to clean the sensor and sniffer tube. I am glad I decided to do it I had a some carbon build up in both sensors.
You will need a few things.
1. A new Gasket set (two gaskets per sensor)
2. A can of Yamaha Combustion Chamber Cleaner.
3. A Oxygen sensor socket 22mm or 7/8" they measure the same. I got mine at Harbor Freight Tools for $9.00. It is a special socket with a groove cut in the side to allow the wires to exit the side of the socket while removing the sensor.
4. A 10mm socket and socket wrench.
5. A torque wrench.
6. About 6 wire ties.
7. stiff tooth brush.
1. First cut the wire ties off the bundled wires that are holding the 4 wires from the oxygen sensor.
2.Now cut the wire tie that is holding the rubber boot and wires on top of the oxygen sensor housing. You can now slide the rubber boot up the wires off of the oxygen sensor housing.
3. Unclip the two wire connectors that are attached to the 4 wires on the Oxygen Sensor leads.
4. Remove the two 10mm bolts that hold the Oxygen Sensor cover in place. Now carefully lift up on the cover and remove it off of the Oxygen Sensor. The area where the rubber boot was has a slot in the back so it can be removed from the sensor wires. Be careful and gentle not to damage the wires or sensor.
5. Take the Oxygen Sensor socket and carefully place it on the nut that loosens the sensor. Make sure you push the wire shield down toward the sensor. This will protect the wires from damage while loosening the sensor. Now loosen the sensor but do not remove it. The sensor is torqued to 35lbs so it will be tight. You must loosen the sensor before removing the bronze sensor mount.!!!
6. Now remove the three 10mm bolts from the bronze housing. You can now remove the bronze housing and then remove the Oxygen sensor. Set them on a clean towel.
7. If you look at where the bronze housing was on the motor block, you will see a little round tube looking thing sticking out about 1/4 of a inch. This is the sniffer tube. Gently but firmly wiggle and pull on the sniffer tube until it comes out it is one piece. There will probably be some carbon and maybe a trace or oil on the sniffer tube.
8. spray about 1" of the Combustion Chamber Cleaner into a clear glass (Not a plastic cup!!!)so you can see the liquid. Put the perforated part of the sensor in the liquid to soak. (DO NOT SUBMERGE THE SENSOR PAST THE PERFORATED BOTTOM PORTION THE THREADS SHOULD NOT BE IN THE CLEANER.) While this is soaking you can clean the bronze housing and sniffer tube by gently scraping scrubbing brushing and soaking these in another glass with cleaner. There will be some hard carbon buildup on these parts so try to get most of it off. Inside the bronze housing I used a cloth towel with cleaner wrapped around a philips head screw driver to clean out all the recessed areas and it worked well. Make sure the hole in the sniffer tube is clear of debris.
9. After the bronze housing and sniffer tube are clean dry them off with a clean towel and set them aside for now. Now take the sensor out of the cleaner and gently brush the sensor with a tooth brush there should not be much build up on the sensor itself. Most of the build up will be in the housing and the sniffer tube. Now gently dry the sensor with a towel and a little compressed air if you have a compressor. If not just let it air dry for about 45 minutes.
10. Now remove the old gaskets off the motor and look where you removed the sniffer tube. You might have to do some cleaning in the hole where it came out of. Just use a clean towel and a little cleaner and it will come clean. I used a single edge box cutter blade to remove all the gasket material that was left on the motor block.
Now you are ready to reassemble!!
1. Place the cleaned sniffer tube back into its cleaned home in the motor block so you do not forget it.
2. Screw the cleaned Oxygen Sensor finger tight into the clean sensor housing.
3. Place the large gasket for the plastic housing in place making sure the hole lines up with the bolt hole. it is a sticky gasket and will adhere to the motor block.
4. Insert the three bolts into the bronze sensor housing and place the small gasket on the bottom two bolts in the correct direction. Now line up the sensor bolts with the holes and finger tighten the bolts. I first tightened the bolts to 3.5 lbs first then retightened them each a little at a time until the specified 10lbs of torque was reached.
5. Now carefully place the Oxygen Sensor socket onto the Oxygen Sensor being careful not to damage the sensor or wires. Now torque the sensor to the specified 35lbs.
6. Carefully slide the plastic housing over the wires and back into position over the Oxygen Sensor and housing. Be careful not to damage the wires or cover gasket.
7. Place the two cover bolts in the holes and tighten them to the specified 6.5 lbs of torque.
8. Slide the rubber boot back over the top of the plastic cover and put a wire tie to hold the wires and rubber cap in place.
9. Re-connect the two wire connectors and re bundle the wires with wire ties.
You are now done!!!!! It sounds long but it is very easy to do. It took me about 1 1/2 hour to do both of my motors Oxygen Sensors and most of the time was spent cleaning the parts and letting them dry...
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