Topic: oil tank/pump question CB750

[dboblet]

I had my bike running for the first time in 20 years (like YEAH!).  Before doing any of this I changed the oil and filter, all of which looked just fine, no signs of rust, no signs of grit, everything looking like it probably did 20 years ago.  BUT...
When I fired it back up (after putting in the oil until the  'full' mark on the dip stick (without running the engine first), the oil tank filled to over filling.  I pulled the dip stick to check the oil level and look for signs the oil was circulating and the oil poured out of the top of the tank.  I then drained out the oil from the drain plug on the tank, until approximately the right level, then fired it up again.  Over a bit of time the oil level went up a bit again, then stabilized.

So... what the heck is going on??  My hypothesis is that there was oil in the bike and that when it started pumping, the excess oil, now a bit warmer and flowing, was pumped into the oil tank.  I'm going to do another oil change since the oil now looks noticeably darker than the fresh new oil I added before all this began.  Any thoughts?

[Bodi]

Totally normal. Oil seeps past the pump back into the sump of the motor, especially after a long time. There's a valve to prevent this but some leak a lot and they all leak a little... after a year or more you'll have oil in the motor for sure. You can just drain the oil pan with the drain bolt down there, or run it a while to pump it all up to the tank before draining the tank.
Your oil looks dark now because it's mixed with the old oil that was in the motor. You can either not worry about it (like I would - you should have mostly new oil) and change the next time a bit early, or do another change to all fresh oil.

[ev0lution7]

congrats.....

i just fired mine up a few weeks ago to find the same thing totally normal....

[dboblet]

Oh, is THAT all it is.  Somehow I expected an answer something like that.  Thanks a bunch guys.