Chatter sound-can someone help

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#1
I just got an 03 yz450f and heard that there is some sort of clutch chatter problem that can be easily fixed??? I did a search and can't find the thread. So I was wondering if any of you know anything about this, or what it could be? My bike has a definate chatter to it, i'm not quite sure if its the clutch. Any help would be appreciated. Thanks.
 

SFO

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#2
I believe there is a yamaha wrench report that lists the part#'s for the appropriate parts to fix this.
Check your dealer and their service writer in regards to this.
 
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#3
The chatter occurs when the clutch is being engaged. It is more pronounced when the engine is still cold. The fix will not fix any chatter when the clutch is completely engaged when you're riding around.
 
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#4
Anssi,

Ok...thanks for the advice. I noticed the chatter when I was riding a little bit slower and then getting on the gas. Is anything being damaged by it? Did you do the mod to your clutch? If you did, was there any difference in performance?

What other mods have you done to your bike? Is there anything I need to be aware of? I heard a 4oz flywheel weight helps out. Mine has a one larger toothe rear sprocket (49).

To be honest, from all of the reviews I was expecting this bike to be too much to handle, and to my surprise it wasn't at all. I DID NOT notice any "hit" like people said (i'm comparing it to a CRF). The bike was so smoothe, yet had tons of power. I had a blast riding it for the first time last night. I am so glad that I stuck with Yamaha on this one.

Thanks for all the info.
 
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#5
Alot of them chug and chatter when your to low in the RPM for the motors liking, even though it has plenty of grunt lugging. Fly wheel weight should help with that though and it should loosen up a bit as it breaks in.
 
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#7
IF you are talking about a marbles in a can sound with the RPM down low while getting on it. I would make sure you are not lugging it too much at low RPM. I would gear down with a larger sprocket in the rear maybe. Make sure you are using premium gas. I use a little Octane boost too. My friend has the 03' and with that 4 speed tranny first seems really high.
 

BSWIFT

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#8
The chatter that you hear may be "chain slap".&nbsp; I'm running a 13:48 sproket combo and the chain really slaps the rub guard.&nbsp; The stock 14T sprocket does not cause quite as much chatter with the proper chain adjustment.&nbsp; Don't forget that the big 450's eat chains and sprockets.&nbsp; Keep an I on your chain adjustment and sprocket wear.&nbsp;
As far a lugging the engine at low RPM's, I don't think you have any issues.&nbsp; However, if your running real rich, lugging the engine will really give you a bog or blubber in your acceleration.&nbsp; If your jetting is good, lug to your hearts content but your engine is made to rev, so twist your right wrist a bit more often. :p :laugh:
 
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#9
I think you are right with the chain slap. I paid close attention to the countersprocket area and chain and it seems to come from that region, although I couldn't really see if it was slapping. I originally thought it was clutch chatter because I read articles on the 450f having bad clutch chatter.

Anyway, would you recommend that I change both sprockets and chain? The bike came with a 49 tooth steal rear sprocket. It doesn't look worn, but the chain seems pretty loose when wiggling it side to side. I have a new chain, but should I also get both new sprockets or just rear when replacing the chain? Any brand that is "better" than others? Thanks.
 

BSWIFT

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#10
Originally posted by boardadikt
Anyway, would you recommend that I change both sprockets and chain? The bike came with a 49 tooth steal rear sprocket. It doesn't look worn, but the chain seems pretty loose when wiggling it side to side. I have a new chain, but should I also get both new sprockets or just rear when replacing the chain? Any brand that is "better" than others? Thanks.
Stay with the steel sprockets and a good chain.&nbsp; The 450's will eat alluminum like butter.&nbsp; Replace them all at once.&nbsp; I'm due myself.
 

Treejumper

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#11
Originally posted by BSWIFT


Stay with the steel sprockets and a good chain.&nbsp; The 450's will eat alluminum like butter.&nbsp; Replace them all at once.&nbsp; I'm due myself.
So far i've found mine to eat them both at about the same rate. Also agree on the chatter coming from the chain while lugging the motor especially if i'm a gear to high. Only thing about the 13 tooth sprocket is i run out of top speed on open stretches and sounds like the motors going to blow. So i put a 14 tooth front on for normal riding and 13 tooth for tight woods.
 

BSWIFT

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#12
TJ, the 13T and 14T change outs were my original intentions as well.&nbsp; I think I may go with a 14:50 or a 14:51 this time around.
 

Treejumper

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#13
I have 13:49 as i couldnt remember what was on the back. The site i looked at said 49 but actual one was 48. Paragon is really tight in afew sections and i only found a couple spots that i would of liked afew more teeth on the back.