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Top end doesn't sound right?

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Hey guys, bought a used bike... Valves or top end DOES NOT sound right. Please tell me if you know what it is because I would rather fix the issue before it turns catastrophic. Here's the YouTube link to my actual bike:

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Sounds like it would be a good time to break out the tools and install a new top end and check the valves. You bought a MX, and this needs to be done regularly. Might as well learn how to do it now.

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Don't run it or rev it. Sounds an awful lot like mine when I dropped a valve. My valve broke on the top of the valve where the retainers held it. You can prolly pull the cap off the head and check the valves, and spot if a valve dropped.

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Yes to all above. Dont run it. Take it apart. Head off, valves and springs out. Cylinder off. Piston out. Check and inspect each part closely.

When you put it back together you'll know what you got.

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I just went through one of my bikes and had a thought about yours along the way.
Check your chain tensioner. It may be that the ratchet is not latching properly, allowing the cam chain to slap. That would sound like what you have there.

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my 15 made the same exact noise. Your talking about the random kinda ticking noise? I brought mine to my mechanic and it was a combo of the idle being to low and something with the decompression system. Been doing it for a while now and when we checked the valves over this past winter everything was right in OEM spec. Try bumping the idle a bit

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my 15 made the same exact noise. Your talking about the random kinda ticking noise? I brought mine to my mechanic and it was a combo of the idle being to low and something with the decompression system. Been doing it for a while now and when we checked the valves over this past winter everything was right in OEM spec. Try bumping the idle a bit



Okay, because it really only does it whenever I'm warming up the bike without giving it any throttle, but whenever I give it just a little gas it goes away. I'll try the idle

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It's been cold up near me and when I first start the bike it idles super low for a second before the high idle kicks in and my bike still makes the noise. Once it's warmed up it goes away. Only happens when it's idling low 

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At first when I got the bike. (9 hours) I messed with the idle screw and ended up setting it low around 1700. Bumped it up to 2100 and the noise is pretty much gone expect for starts on really cold days. 

 

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So ,.... is there seeming to be consensus then to be forming that:    perhaps the spring tension on the decompression link may be just a bit tight on these newer bikes that are noisy at idle?  The test to confirm would be whomever has a noisy top end like this; the next time it is open to go ahead and take that spring off, stretch it a bit so is not so taught, and reinstall.  Then see if the problem has gone away and let us all know.  

 

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Edited by FaceDeAce

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