https://drive.google.com/file/d/1_UyK8y5a8OdxYLE8g0sduBOc4eIFI0kI/view?usp=sharing
COG Chalkdust DIY: https://concours.org/Tech-Pages well worth the cost of joining. You get gems like this:Valve cover leaks / Exhaust Camshaft sensor O ring
Another source of oil leaks in the left forward side of the head is the exhaust cam position sensor. This sensor is installed in the front side of the head and secured with a 10mm bolt. The sensor has a small O ring installed on it that is intended to prevent oil from leaking out of the head. The problem is when the bike is shut off, oil pools in the front left corner of the head when on the side stand, so this sensor as well as the valve cover gasket in this area is totally submerged in oil for long periods of time. If there is even the tiniest fault or gap in either the valve cover gasket or cam position sensor, oil will find a way to migrate through it. What Kawasaki should have done is provide an oil drain back hole in the front side of the head so that oil wouldn’t pool in this location when the engine is shut off. The O ring on the exhaust cam sensor also appears to be a bit undersized, and doesn’t always provide a tight enough fit to prevent oil leaks. And since this sensor is right under the left forward side of the valve cover gasket, it can sometimes make it hard to tell if the leak is coming from the gasket or the sensor. The best way to determine where a leak is coming from is to first clean the entire area, and then see if you can observe with a bright light where the leak returns from. Another old trick is to clean up any existing oil and then spray some talcum powder around the suspect area, and then look for traces of the leak in the powder.
Folks on the COG forum have discussed the cam sensor O ring topic at length, and after some measurements of the O ring were taken, a suitable substitute for it has been located that will provide a better fit than the original. I located a place on-line that sells this size O ring for 93 cents each. If you go to http://www.theoringstore.com and search for V2.40X016.3 it should bring up a page with an O ring in the proper size. The dimensions of the O ring are 2.4mm by 16.3mm and it is made of Viton which is good to about 400 degrees F. Another source located is through McMaster-Carr (http://www.mcmaster.com) and their part number is 9263K686. The only downside to purchasing them from McMaster-Carr is you have to buy them in packs of 20 for $12, so you might want to share a few with any other owners you meet at COG rallies if you order a pack from them.






































