I bought a 2000 400ex and i am having trouble with the oil, i got it in december and ran it from when i bought it till like february it used no oil, then one day after that i checked it and there was no oil in the tank..i was like oh geez so i put some in and ran it..next time i checked it no oil again..so my friend changed the oil for me while i was at school and i went to the cochranton poker run, when i got home i checked it, the oil was down a bit..then the following weekend i rode friday and saturday all day and then this weekend i got it out checked it and again no oil...its really angering me..there are no knocking noises, no smoke, and no leaks...the oil is just disapearing..if anyone can help or is having the same problem please email me at travass99@aol.com...thanks.

 

How are you checking your oil? The manual says to start your motor, run it until the motor gets to operating temperature, shut the motor off, let it sit for 5 minutes, and then unscrew the cap, wipe the oil off, and set the cap and dip stick back in. DO NOT SCREW IT IN THOUGH. Take it out and read it from there.

 

You may have a check valve problem that is if they have one in the tank or line.
If this is so your oil is going to your crankcase,
a dry sump system holds oil in a tank then takes it as needed to the crankcase & other parts of the engine.
I have some older harleys that this has been a problem with.
Dont know if this is your problem but it is a thought.