Ive blown two motors with this stuff, one brand new and one old. Both times i was on a long ride, at least an hour and a half or so. You'll hear the tell tale signs of the crank bearings getting cooked, you can baby it for a while but one 15 second rip at full throttle and the bearings grenade. I took both motors apart when i got home and they both had cooked bearings. I think this stuff is ok on short little trips and bombing around for a bit and it totally makes your bike faster and run better but i dont think im going to use this stuff again.