an oil worth taking a look at is Dumonde Tech (
www.dumondetech.com ). The mostly preform resurch and development for other oil companies but thier oil works well.
My 1999 YZ125 went from doing a top end every few rides (5 to mebe 10 hrs) on Yamalube 2-R to about every 25 hours when i swiched in 2000. other then pistons, clutches and shift shafts (over time the splines ware out). I have not done anything to the bike
The bike has about 1900 hours* and when i did the last top end the bottom end was as tight as new
This bike still runs like new!
I wish i knew enough about lubrication to know what to look for, but I have been having much grater sucsess with dumonde tech then my ridding buddys and I have with other oils. If there is somthing else better of any oil tests / studdies i would love to see it.
* from 1999 to 2002 i rode at least 2 times a week for at least 3 hours per day (probablly 4 or 5 hours per day but cannot prove it so i rounded down). the hours during this time peiriod= 1200 hours; 2003-2009 I started ridding my k5 more frequently (bought in 2002 to play on the trails/ dunes) riding one day every other week at 4 hours a day = 700 hours
