Motorcycle Repair: 1990 FXR lost oil pressure after change, tank lines, oil light

Question
QUESTION: My 1990 fxr lost pressure after i changed the oil.  I am only running 10 lbs now at a cold idle instead of around 30-50.  I was told that I may have put too much in.  I put 3 quarts of 20-50 in the tank and it brought it up to the top line on the stick.  So I lowered it to 2.5 quarts and still have low pressure.  It will go up to about 20-25 lbs if reved some after start. My oil light stays off now which is good so what do you think could be my problem?

ANSWER: You didnt drop anything in the tank did you?
Mike

---------- FOLLOW-UP ----------

QUESTION: No, I removed the tank, lines, and cooler.  I cleaned them all out with gas making sure none was left in the tank, or lines.  I placed everything back in proper order (as far as I know) I fired the bike back up and I had close to 30lbs of pressure then dropped to around 15 after a min or so.  But what was really strange is when I checked the oil after this it had a ton of little bubbles in it.  It looked foamy.  just to be sure what is the oil line routing for this bike?  Again 1990 fxr lowrider with an oil cooler  thanks

Answer
The bubbles is from having so much air in the lines, it will clear up over time. I think after cleaning everything out you probably have air still int he lines. As long as you have pressure go for a ride and see if the pressure doenst go up
Good luck and happy riding
Mike