Was able to get away to ride this weekend, first ride of the year. Bike was running like a champ, then we stopped for lunch. After lunch I start her up and it is making a really irregular clatter noise from the top end that jars the bike whenever it makes the noise. After warming up the noise stopped and we took off toward home. About 1.5 miles in the engine just siezed up and we skidded to a halt. Now I can't even kick it over. I'm thinking I dropped a valve or something. I can't believe how bad this blows. I maintain the bike very well as far as oil changes and air filters go, but I had yet to check the valves. Do you guys think it is a valve issue? Guesstimate how much do you think this will set me back?