My sons 250x has never given any trouble and cranks easy, however, my neighbors, a 2006 250x has been nothing but problems. It has been to the Honda shop, I think, 4 times now in 2 years. Each time they redo the valves, it runs and cranks well for about 8 hrs ride time, then goes back to the same old problem. Several questions, Do the valves "settle in" or do they just get worse and worse? My thoughts are if they, I'll make up something, wear off .008 mm from correct setting and settle in, then why not adjust/set them off .008 from the Honda shop and when they wear in in 8 hours, they will be right? I have refrained from working on this bike because I don't need another responsibility, however, he can't sell it like this. Nor does he ride with us any longer, thus reducing my chances to ride. I have never done this style of valves. If I recall, it is with shims rather than adjusting the way I am accustomed to. Is this something I can fix for him, or best to stay far away from it? I have rebuilt many dirt bike motors, yet, not with this style of valves. I have the complete service manual. I just need to know if it can be adjusted to a point that it can be ridden for 50 hours without needing it again.