Hi guys I was riding my bike yesterday training for a 6 hour long cross country race coming up in 2 weeks and near the end of the day my bike started to get really loud in the engine, so I turned around and babied the bike back to my truck and shut it down to let it cool down. After awhile I decided to investigate if the noise was still there or if it was just me being me and worrying over my pride and joy haha. So I went to try and start my bike and found I had no compression and could just push the kick start lever all the way through the stroke with my hand, I packed up and loaded the bike straight after I found that out and went home. When I got home I washed the bike and then blew it dry (as I always do after washing it) with compressed air and parked it up for the night to inspect it the next day. I started with the most simple things as checking if the spark plug had not come loose but it was in tight, so I then went to the next step. I removed the cam cover and inspected the clearances on the valves and got a shock to find that all but 1 exhaust valve was out of spec. My one intake valve was so tight that I could not even get a 0.04mm feeler gage in and the other intake valve was 0.20mm clearance (spec is between 0.10mm - 0.15mm for intake) as for the exhaust the one was in spec at 0.23mm but the other one was out at 0.30mm. I had checked my valve clearances 10 hours before this happened and they had still not moved from factory from when I replaced the piston and rings at 66 hours. The timing was all still 100% correct as i also fitted a new cam chain while i was in there for cheap assurance. I have taken the bike to the dealers and asked them to have a look and see what has happened as they told me that it is the first time they have heard of this happening is only 76 hours engine time..... like they always say haha. I am very good with maintenance (even the ex can agree on that... haha) and my mates always joke and tell me that I almost do over maintenance as the bike and air filter is cleaned after every ride and I change the oil every 6 hours with a new OEM oil filter. I use Motul 300V engine oil and Motul air filter oil as I believe what you put in is what you get out. So the question is, has this happened to anyone else at the amount of hours that I have ? as I have always been told that Yamaha is very good in regards to valves.