A Honda 400ex is rated to hold 5 quarts of motor oil. This includes the oil stored in the oil pan and the filter which are replaced during an oil change.
about 2 qt.
2.3 quarts
1.9 US qts. Be sure to drain oilpan AND crankcase when changing oil.
1.9 us quarts
GN4 Honda oil only.
2.6 quarts
2.6 Quarts
10w-40 G4
on the right side of the motor there is a cap with twwo bolts take that off and theres th oil filter it will have a oil line running to it
it should be in your manual (pretty recent machine), could have a sight window and or writte as a part of the casting and if all else fails, call the dealer
On a 400ex the engine and transmission share the same oil. So when you change the oil in the engine you are changing the transmission oil as well. That is why you need an ATV or motorcycle oil designed for wet clutches.
A Honda CT110 will take 0.9 liters of oil