weird thumping noise-diagnosis?

[SVR6]

While riding Long Lake single track in Mich. Friday morning, I started noticing what sounded/felt like the engine was moving in the frame. I would feel/hear a thump when going over woops.

Last night I removed the rear swing arm thinking that the link bearing were shot - they are fine. The only thing I found was a missing nut on the link holding the bottom of the shock. Check some of the engine mount bolts and they are tight. I'll keep checking them and starting to wonder if there is free play between the engine rear mount and the swingarm pivot bolt.

since I'm running out of ideas... can someone suggest another cause?

I'll be riding tonight on a borrowed x model in the meantime.

Thanks

Stephen

[tvalliere220]

It's probably your chain slapping of your swing arm. Ride it!!

[SVR6]

No it's a hard clucking sound. I was told to check the lower eyelet of the shock. Any other suggestions?

[tvalliere220]

Does it happen when idling? Put it on a stand and check for up and down and side to side play.

[SVR6]

No only on the downside of bumps or woops or when going downhill.

[tvalliere220]

Yea check your swingarm for play.

[teamdooracer]

Also check your rear wheel bearings. I have seen them go bad and let the wheel clunk back and forth.

[SVR6]

Starting to wonder if the shock is shot....

[tvalliere220]

Check all the bearings for play first!!!

[SVR6]

Got the swingarm back in after loosening the motor mt bolts and tweaking the rear of the motor left. Once we got everything back, noticed 1/16-1/8" play in the frame top shock braket. Also observed a missing exhaust bolt. Replacing fasterners and using blue locktite!

We'll have to drill the frame and sleeve it.

Edited June 7, 2011 by SVR6
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