Yamaha R1 opening up engine after dropped valve .

[@plllot9713]

did you manage to figure out what happened? valve clearance too big? I've seen on the internet it happens do R1s. I used to have an MT09, they have valve checks every 40kkm, it it similar with the R1? Did you rebuild it or you found another engine?

[@Republicofcomposites]

Hello, I think its just age. This bike was used in endurance racing and had never been checked after they only come to the shop when it was broken. So I think most of the problem is no checks in time. They changed the complete engine. With this dmg I told them it wil be risky to trust the rod is stil ok , the cranckshaft got a hit so you dont know how bad that is . Checking all this replacing it and rebuilding it was more expensive than finding a good road engine.