Those not familiar with the oil change procedure on a YZF frequently get it wrong. This is written as a reference for those who have just acquired an '10-'12 YZ450, but didn't get a manual with it. If you don't have one already, start by downloading a manual here: http://www.yamaha-mo...ice/manuals.jsp Or Here: http://www.yamahaown...ook.com.au/?r=0 You should also understand that the motorcycle has a dry sump oiling system, wherein the oil is stored in separate area, pumped from there to the lube points, then picked up and returned to the "tank". In the '10-'12 models, the "tank" is a reservoir built into the front of the crankcase assembly just in front of the actual crankshaft cavity. Thus, the sight glass is located on the left side top of the crankcase in front of the cylinder. The engine must have been run within 10 minutes prior to checking the level, or the oil may begin to drain back into the crankcases, and your reading will be inaccurate. Read also: http://www.thumperta...903#post5221903 Simplified oil change procedure: Start and run the engine for about one minute and shut down. Remove the filler cap to help the engine vent better. Remove the drain bolt from the right side, above the frame rail, below the water pump. This drains the "tank" section Replace the bolt. Remove the oil filter cover and replace the filter (or clean it if using stainless mesh. Do not reuse brass mesh filters) Replace the cover. Remove the drain bolt from the crankcase, located behind the right side frame rail on the bottom rear corner of the transmission, angled straight out toward the frame. Replace when it finishes draining. Refill the system at the fill port on the left crankcase cover. Refill with 1.0 liter if you changed the filter, or 1 quart (0.95L) if you didn't Start the engine, run for at least one minute, shut down, wait 30 seconds and check your oil level with the bike level and upright. Torque wrenches should not be necessary if you have a reasonable level of skill and common sense.