I’m getting what sounds like valve rattle at 20mph & above. It’s been doing it since I got it new, now has 30hrs on it. Mainly used for hunting. I changed the oil (all Yamaha stuff) at 20hrs. Took it to a dealer this summer with the concern & they said it was normal, but still sounds a little funny. I’ve had several Hondas but decided on this one. Good reviews & more bang for the buck (auto trans, independent rear, etc). I’m pretty mechanical but don’t want to tear it down if it’s normal. I know it’s hard to determine noises without hearing them. It’s not excessive just not as quiet. Also bought a 700 at the same time but didn’t need both so I sold it. Thinking about taking it to a different dealer for a 2nd opinion. Any advice or experience would be appreciated. Thanks

 

You could adjust the valve clearances, to be sure that it isn't simply excessive valve lash. Some engines are noisier than others, can't say I've noticed 450 Yams being particularly noisy engines but they are not the quietest either. I did have a 550 Yam with a loose centrifugal clutch drum (they are riveted onto the variator shaft) that was quite noisy.