OK guys, I could sure use your help. 2013 Yamaha f 200i4. Gear Lube: first change gear lube, honey coloured same colour as installed. Amsoil synthetic 75/90 . Second lube change Amsoil, after 100 hours drained BLACK Third lube change Amsoil, 65 hours drained Black. From light honey coloured to black in less than 100 hours. No sign of metal bits on the drain plug. No marine teck around here can come up with any clues to this issue. Concerned it may be a warranty issue ( 6 months left on the warranty). Nothing appears to be any different in performance. Changed yesterday to Mercury high performance gear lube to possibly alliveate the problem, but only time will tell. Would appreciate very much any input you knowledgable guys could provide. Not sure the cost of dismantling the gear case to inspect, no doubt on my dime, until proven it is a warranty issue. Over heating gear casing was mentioned, but how is that possible submerged in water, with no burnt smell in the oil. Synthetic gear oil stinks regardless! Thanks Guys, looking forward to a possible explanation. Cheers, trapper