THE yz450 noise, need closure

[blue9red9]

I'm talking about the clink clink noise at idle. I have a well worn 06 yz450f. My brother has a brand new 07 yz450f. The noise is there on both bikes. However in my 06, it is louder. Has anyone determined what the noise is? What would it mean when it gets a little louder? I've checked the 06 valves... good. Always starts right up. Runs great. The 06 noise doesn't get louder when you rev it but actually appears to go away at anything other than idle. The bikes sound the same off idle. This is driving me nuts. What's the noise?

[grayracer513]

Camshaft rattle, timing chain noise, and transmission and primary gear torsional rattle. All normal. It could have been made quieter, but that would not have made it faster or lighter.

[Ga450owner]

They are all noisy....add a skidplate w/ foam - this seems to quiet them down a bit..soundproofing:p

[YzGuy79]

hmmm. I see things haven't changed. I thought my '03 (my 1st 4st) was falling apart when I started it. I even took it back to the shop. The guy smiled and said "yeah that's normal." At idle you are hearing the valve train noise. As long as your valve are in spec, don't worry.

[VB_Racing]

I run a GYTR insert in the stock exhaust of my WR450, and the thing sounds terrible all the time, I would get paranoid about all the noises I would hear!!

Unplug the exhaust and it would sound normal!!

I have had 3 Yamaha 4stk's 1 400, and 2 450's. They are all loud, but run forever.

On the flip side, my 07 CRF450 is alot quieter at idle, but service life sure does seem to shorter, go figure!!

Dave

[kyle450rider]

my 2007 has 13 hours on it and the noise i can hear it at idle and during riding the thing.Drives me crazy!It seemed to get louder after i adjusted the valves.

[02YZ426]

I don't like the sound of it either.. but it goes away soon as I hit the gas. If it was something to worry about I would suspect the sound would get louder when you rev it.

[blue9red9]

Misery loves company... I guess as they get a little older, the noise may change. As long as it's not the big end of the rod cause that's what I see in my mind when I hear the noise.

[Wyatt]

If you are not very familiar with these bikes, get someone who is to listen to it. My friends '06 got noticably louder than mine and we knew something was wrong. They all make noise, but this was a touch out of the ordinary. He tore it down to find the big end rod bearing was failing. This was certainly not a noise that he should have ignored and kept on riding.

[2wheels-drz]

the noise scares me too....sounds like an old cement mixer at idle. but they all do it, so its ok...

[pace]

If you think your Yamaha is noisy, go stand next to an idling KTM some time. My 525EXC sounds like it's coming apart at idle, and has ever since new. My YZF has a much quieter motor.

[jayh300]

If you think your Yamaha is noisy, go stand next to an idling KTM some time. My 525EXC sounds like it's coming apart at idle, and has ever since new. My YZF has a much quieter motor.

or a 'berg... A friend of mine has a 501 and sounds like a grinder running.