My name is Jared and I am kind of new to the YZ forums. I had two crf 450's previous to this bike (a 2008 and a 2009). When I was in high school I had a 1999 YZ400F (an excellent bike). The crank recently failed on my 2009 CRF450r and I bought a very clean used 2007 YZ450F. I have been very happy with the YZ (although I have only put 10 hours on it) but it has been burning oil. For example: I recently raced a two hour hare scramble (riding the bike very hard) and burnt half of a quart of oil doing so. I knew that the bike was burning oil previous to this so i have been keeping an eye on it. I changed oil on it today and measured this half quart loss and tore the filter apart to inspect it. When I did so I was disappointed to find a lot of steel and aluminum in the filter. It is excessive and I suspect it to be from the piston and cylinder since the machine also burns oil. I did disassemble the clutch to ensure that the steel was not coming from the plates in it, and they looked fine.
As I said I bought this bike used, but it was very clean and still had the original grips, stickers and tires on it. I suspect that somebody ran the bike out of oil or did something else ignorant with it. I am asking for your guys' help suggestions and tips as to where the oil loss and material in the filter are coming from as well as the action that I should take to repair it. I appreciate any suggestions questions and or comments that come my way. Thank you.
Edited by squirrel 830, October 21, 2012 - 07:34 PM.