[SpudRider]

I'm glad the Castrol motor oil is working well for you, Dave.

I use Mobil, Delvac, 15W/40 motor oil in all my motorcycles. I don't know if it is JASO certified, but it does a superb job protecting my engines, and the clutches work great. My Zongshen ZS200GY-2 is approaching 70,000 miles on the odometer using this motor oil.

I have not heard of anyone having problems with Shell Rotella T. If you do a search for Shell Rotella T on Thumpertalk, ADVRider, et cetera, you will find many happy customers. I use Mobil Delvac because it works great, and I can buy it for $13/gallon at several local stores.

Every year Mobil offers a $5 rebate per gallon for Mobil Delvac. I always stock up at the time of the rebate, so I get my 15W/40 motor oil for $8/gallon.

Here are two interesting articles on motorcycle motor oil.

http://www.calsci.com/motorcycleinfo/Oils1.html
http://www.calsci.com/motorcycleinfo/Consumables.html

Here is a link to an interesting thread on the topic of motor oil.

http://www.chinariders.net/showthread.php?t=13021