Topic: Another oil line question

[74cbracer]

This is driving me nuts...  My '74 CB750 has under 9000 miles on it.  Was sitting for about 3 years when I got hold of it.  I know the previous owner and he never had any problems with it.  The motor and trans were not opened up but, everything was cleaned and polished and the bike turned out quite nice. 
Now I go to run it for the first time and all checks out.  When I get back home my rear tire is covered with oil. 
Vent line from the oil tank.  Yes, yes go ahead and laugh (I can now)
Oil level is slightly under half on the stick with warm motor
Oil lines are correct
Valve cover line is clear and free flowing
Only happens over 50MPH or so.  I've run around with the vent hose in a small plastic bottle and that overflowed the other morning going to work
Am I missing something here???    I understand that the trans makes pressure at higher speeds.  I get that.  Why is the tank not working right???
I hate cleaning oil off of chrome and paint
HELP

[scottly]

1) oil vent/drain lines not properly connected
2) over-filled oil tank

[Silverback]

You can potentially have a problem with the check valve in your pump. This results in a more than desirable amount of oil in the case and what seems to be low oil in the tank. As you keep adding oil to the said level in the tank, the case continues to fill and internal pressures force it out the vent. Just a thought. Have you drained the oil from your case. I was having what I thought was an oil consumption issue and couldn't find any leaks until one day oil started forcing itself out the vents and case covers. When I drained the oil from the pan/case it was obvious that there was way too much oil in the bike.

[754]

When you said 3 qts, was that after you had drained oil pan and tank?
 If so that should be near correct amount.