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tnat1

2006 YZ450f - knocking sound ? video

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I just picked this 2006 yz450 f today and i heard yamahas are noisey but is this normal or consistent with the 450s heres a link, it has 25-30 hrs on it. i hope someone can help me with this im bummed out that maybe i bought a lemon, i got it from a reputable dealer here in illinois in morris il

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I think you need to do a tune-up on that baby stroller........the 450 sounds normal to me...they all seem to sound like manure spreaders...:thumbsup:

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My 426 sounds nothing like that... but hey maybe they're diff. That would scare me if mine sounded like that...

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Yes it is scary. I put a new forged piston in my 06 when I heard what's on that video. Nothing was wrong with the bottom end and now it's louder. I can't believe they turned these bikes out the door sounding like this but they did and it's "normal". Nice stroller, makes me want to take a napie nap laying in the stroller listening to your bike.

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That sounds like your valve train. Remember one thing that is happening lately is mfg's are putting quieter exhausts on bikes. With this happening your hearing more engine noise. In that motor you have 2 cams, cam chain 5 valves, 5 valve springs besides your piston and crank. You will hear some noise. I'd just measure your valve clearance to make sure they are in spec. I remember the first time I switched to a quieter exhaust i thought my bike was going to blow up because i could hear the valve train.

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Sounds like the typical "pipefitter's convention" you hear from these at idle. It should be quieter as you bring the RPM up a bit.

The best way to approach these questions is to make a direct comparison to another similar unit in person. As good as current technology is, videos and other electronic recordings are rarely very "real" sounding, and are therefore hard to gauge from this end.

Things you might want to check if you're convinced the noise is abnormal, and it does diminish with rpm and load, would be the nuts/bolts holding the clutch boss, main drive gear, and balancer shaft gears on. There should, of course, be no reason for these to be loose, but it could be.

Note that the aluminum frame attenuates noises from the engine, whereas the older steel frames damp them.

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Thanks for the Information, im going to check the valve clearence and ill check the primary side nuts and such, to just do a once over on it.

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Hey guys don't want to scare any one but a friend of mines 06 sounded like that and he needed crank bearings. I know of several late model YZ 450s that had this problem. I would pull of the ignition cover, grab the flywheel and see if there is any play in the crank. If in doubt I would have a tech check it out.

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Would the sound get worse when the motor gets reved up if it was the crank bearings?

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I just picked this 2006 yz450 f today and i heard yamahas are noisey but is this normal or consistent with the 450s heres a link, it has 25-30 hrs on it. i hope someone can help me with this im bummed out that maybe i bought a lemon, i got it from a reputable dealer here in illinois in morris il

please do not tell me you bought that from pro source motorsports...... does it have an FMF sticker on the front fender, with some wierd looking white and black suspension stickers? I think i saw the shock sticker in the vid. If this is it, you MIGHT have a problem. i went and rode that bike a month ago before i got mine and i hope you looked it over very well before you bought it. cause if you didnt, you will notice the back of the bike is bent a little, (think just subframe), but if you look above the front sporcket the peice that holds it on there and the cases are all chewed up from a chain bein thrown off and bustin the cases, also i think the clutch cable bracket is broke. i rode it around for a minute or two and it just didnt feel right. so i didnt get it. too me it seemed everybody that worked there acted wierd when i was there. the guy who showed me around didnt say much of anything when i looked at that certain bike. also the bikes on the showroom floor are worn out pro race bikes that they put new tires and 30$ shroud graphics on and just painted the clutch covers a different color to make them look new again. (they replace all the major places that show wear)

but hopefully this is a different bike and if its not......good luck, hopefully i just thought something was suspicious when i went and looked at it. :thumbsup:

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Would the sound get worse when the motor gets reved up if it was the crank bearings?
Usually, yes.

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I it knocks worse under a load start worrying , My bike got really loud went i put a skid plate on it ! I took it all apart and all i found was the piston was worn out just a little, There just loud motors keep your helmet on and your legs together and it's quieter

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