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300rr piston slap?

PostPosted: Mon Dec 06, 2021 6:39 pm
by hankbgood
Just did the top end on my 2017 Beta 300rr and it has a strange ticking noise. Does it sound like piston slap? The new cylinder, piston and head were matched but may tear it down to verify. Any feedback would be appreciated. Thanks

https://youtu.be/mRn5RqLbhdE

Re: 300rr piston slap?

PostPosted: Fri Dec 17, 2021 9:24 am
by pauld250rr
Hank did you ever figure out what tje noise was?

Re: 300rr piston slap?

PostPosted: Mon Dec 20, 2021 4:35 am
by Hurky
4 me it definitely sounds like too much piston-2-cylinder clearance and what you hear is the piston skirt 'slapping' against the cylinder wall.

Maybe you installed an forged piston (Wössner. Wiseco..) ? Those require a higher tolerance because they expand more than a cast piston, and that noise could be expected during cold starts, but should minimize once warmed up.

Cheers.

Re: 300rr piston slap?

PostPosted: Mon Dec 20, 2021 7:16 am
by oldman
If the noise is less with the clutch pulled I would suspect some play there instead of piston slap.

Re: 300rr piston slap?

PostPosted: Fri Dec 31, 2021 6:28 am
by hankbgood
The piston is a Wiseco and the ticking wouldn’t go away even when warmed up. I didn’t like how it sounded so I ended up removing the forged piston. I went back to a cast OEM (Vertex) piston and the ticking noise is gone. I appreciate the feedback.