As far as Yamalube goes it is manufactured by one of the biggest oil companies in the business, and works very well. I have just gotten back into Banshee's and atv's for that matter after racing drag bikes. All oils have their pros and cons. Several of the guys that run 2 stroke drag bikes used Yamalube even in the old Kaws. Also, I am a service manager for a Yamaha dealership and I have had many people try and have warranty repairs done. One thing I'm sure of is Yamaha will cover it IF IT IS PROVEN TO BE A FAULTY PART. I can probably right a book on what they won't cover and why Most people that do try and make a claim often do not mix the ratio properly and a huge problem is filters...you'd be amazed at how many people don't clean their air filters. I've been able to get quite a few claims resolved but the majority Yamaha won't cover once they recieve the pistons and it shows being burned up from a lean condition. Basically Yamaha's feelings are 2 stroke atv's are considered for racing purpose and that's the main reason they don't cover crap when it comes to warranty.