Park the vehicle on a level surface. Drain the oil and change the filter. Add 4 quarts of the correct weight oil and start the engine. Let run for 1 minute and shut down. Wait 30 minutes and check the oil level. Add enough oil fill it to the full mark. You now know the capacity.
2.11337 qt
4 and 1/2 or 4 and 3/4 qt
6 qt
0.95 qt for a drain and refill or 1.06 qt after complete disassembly
It should take about 6 Qt's of Motor Oil. Make sure you also change Oil Filter.
8.5 US Qt. (LasVegasEd) including filter
get 3 qt. it takes a little over 2 with an oil and filter change so put about 2.3 qt in and run the bike for a few minutes and check level in the sight glass.
5qts will fill it up, have a 6th qt on hand for top offs
The 2003 YZ 125 manual states Periodic oil change: 0.65 L (0.57 Imp qt, 0.69 US qt) Total amount: 0.70 L (0.62 Imp qt, 0.74 US qt) Hope this helps
12 qt. (11.3L) with filter
Engine oil : 4.2 qt (Oil pan), 0.32 qt (Oil filter) Automatic transaxle : 8.9 qt FWD; 9.3 qt AWD
4.2 qt. (4 liter) It is recommended that you use 0w-30 synthetic oil, if it is not available then 5w-30 should be used.