CRF 450x engine noise at higher rpm

First post so I hope this works. Looks like there is a lot of good knowledge tapping into these forums so I'm hoping to find a little.

Yesterday i noticed a wierd sound coming from my engine. It starts and runs fine but noise like a loose parts badly vibrating starts at a higher RPM. If I rev the engine a little more the noise goes away, when I drop the RPM to the same range the noise comes back and then quits at the same RPM it started. I didn't check it to many times for fear of causing real damage but it seems to be real consistant at the same RPM. Any ideas?

Probably something 'innocuous' like buzzing levers, loose headlight, or similar.

Get a buddy with a good set of ears to help you 'sniff' out where the sound is coming from.

I put a after-market skid plate on mine and it makes odd noise at some RPMs. Do what Krannie says before you take anything apart.

I also have had an aftermarket aluminum skid plate for a couple of years and never had a problem. Out of the blue, my bike started making noises like you describe. I took the skid plate off and, sure enough, it was the problem. I put a couple of strips of tape between the skid plate and the frame and it cured the problem.

Thanks guys. I took the skid plate off and the noise is gone. It is an aluminum after market plate. Must have loosened up just a little.

I just put an aftermarket skid plate on my X after owning it for a year. And my first ride was yesterday and now it has a new rattly sound.

Even with it on there snugly, I understand from other TT posters that this is to be expected as the skidplate reflects the engine sounds back up at you. They are right.

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