When i put 4 litres of oil in the engine the sight glass is full and when i start her the level drops to about half way and only when she is reved it empties and when she is switched of the sight glass fills back up to full. I checked the oil pressure at 4 thousand rpm and it reads about 52 psi which is within the specs in the manual is this the norm with the gpz or do you guys think i have a problem with my lubrication system. All replys welcome