Just doing a complete rebuild on my 2003 WR450F and have a question. I received and installed my new output shaft and transmission shaft bearings to the sprocket side crankcase half, but noticed that the new yamaha oem bearings have come with covers installed on one side of the bearing. I have currently installed both bearings with the covers left in, and facing into the crankcase as per the attached photos but the old bearings had no such covers. Will the covers stop any lubrication reaching the transmission and output shafts gear set. ie: splash fed ?? Will removing the covers create a drop in oil pressure behind the output shaft seal preventing the oil feed behind the collar and into the output shafts internal oil gallery ?? Will it cause a drop in oil pressure to the transmission / clutch shafts oil delivery pipe ?? I'm inclined to remove the covers but these were genuine yamaha bearings i received so i'm a bit confused as to why they would ship with a cover if it wasn't required and needed removing before installation. The bearing part numbers that were ordered and received were 100% correct. Leaving the covers in also makes sense as it would allow the bearings to sit in an oil bath and also maintain oil pressure allowing more oil through the output shafts oil gallery and better pressure to the transmission shafts oil feed pipe. The only problem i can see is that leaving the covers in will prevent splash feeding to the gear set through the bearings race. Im not even sure the gearset gets splash fed from these bearings. Any advice or comments would be appreciated.