about 2 qt.
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.
1.9 US qts. Be sure to drain oilpan AND crankcase when changing oil.
bottom of the motor. if you have a custom skid plate you may need to take it off and cut a hole in 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
You need an 18 mm spark plug socket.
yes i just put one on my 2001 400ex the only thing you really have to do is take the intake manifold and hoen it out some the intake tube is a tite fit but it works
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
take the timing chain cover off and with a wire hanger pull it from the bottom to the top sprocket so it doesn't fall.
2 quarts
make a 400ex faster put a intake, jets, cam, piston recomend a 416, and take some things off that are heavy
a motorcycle grade (moly free for the clutch) 20w-50 JASO rated oil would be great dont use car oil. you could ruin your clutch