Phantom oil leak

'79 KZ650 B3

I have this darn oil leak that comes and goes. It appears to be on the bottom of the engine, so I'm guessing it's either the pan gasket, or a sidecover gasket.

What's strange is, sometimes it leaks, and sometimes it doesn't. It doesn't appear to be tied to the oil level.

After not leaking for weeks, I went out the other morning and there was a big puddle of oil under the bike. I looked as best as I could, but could not see where it was leaking from.

I checked the oil. It was low. It took about 1/3 quart to bring it up into the center of the window. I rode the bike to work and back (about 35 miles).

The next morning, there was no fresh oil under the bike. I checked the oil, it appeared I couldn't see it in the window, so I started pouring it in, checking the oil level window along the while. After about half a quart, it occured to me that maybe I couldn't see the oil in the window because it had someohow become overfilled. I stopped till I could figure that one out. Haven't ridden it since. In the two days since, it has only leaked a few drops.

I don't get it.

Can anyone help?

Thanks

If you leave the petcock in the on position, and have a float valve that doesn't seal, then you could be filling your crankcase with gasolene. That is the only reason for rising oil levels. Unless, someone is tampering with your bike. You could remove the oil fill cap, and smell the oil. If it smells of gasolene, then I would recomend that you change your oil immediately. Of course, you would also need to fix the leaky float valve, and verify the correct function of the petcock.

As for the leak, it is usually helpful to get everything as clean as possible on the motor. It has been suggested to dust the motor with something like baby powder which will indicate the presence of new oil fairly quickly.

Hope this helps.

You are checking the oil level on the center stand every time, right?

Yes