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4-stroke chatter

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I picked up a KTM 350 XCF-W and have been riding it for a couple seasons.  It's my first 4-stroke dirt bike.  Coming from 2-strokes, one of the things I noticed is when you are it too high of a gear and add some throttle you get a chattering sound.  I've noticed it in a lot of 4 stroke videos so I think it's normal and not something unique to KTM.  Anyone know what it is?

I just want to be sure it's not spark knock.  I know what spark knock sounds like on a 2-stroke so I'm 99% sure that's not what it is unless it sounds really different in a 4-stroke.  I'm guessing maybe timing chain noise or something?  

Hopefully it won't cause any problems over the long haul.  I usually avoid it but sometime you end up bogging it up a tough climb and have no option.

Doc

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That's normal sound it's basically the motor trying to die or chug out but it can't because it's still actually moving . Alot of rotating mass clacking around cuz your not in the right gear they all do that to some extent .

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I did some searching, which I should have done before posting, and the consensus is that it's the chain rattling due to the uneven power pulses of a 4-stroke at low RPM.  Just weird it doesn't happen to a 2-stroke.  It's good to know it's just chain rattle and nothing that's hurting anything when it happen.

 

11 minutes ago, S.O.A.N.Z said:

KTM 350 XCF-W  - youre probably not ringing its neck enough

 

Yeah, it only happens to me when I get caught off guard and in the wrong gear.  

Doc

Edited by Doc_d
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It does it on 2 strokes you just don't feel it as bad , why people put fly wheel weights on em to keep em from chugging and help from killing it on slow stuff . Also there's very lil engine braking on a 2 stroke so when your in the wrong gear you don't feel it as bad till your going way to slow 

Edited by Greenwrench

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