Strange Growling/Rumble Sound 06 YZ450F

I have a bike that I let my friend race (he knows what he is doing) and the bike developed what I would call a growling/rumbling noise that seems to be coming from the clutch area. The noise is louder when the clutch lever is out. When you pull the lever in, the noise is still there but not as loud. The clutch seems to be operating properly and you cant feel anything funny happening through the lever travel.

I am leaning towards a throw out bearing or clutch hub bearing going out. Have any of you experienced this noise in the past? I plan on riding the bike in gear to see if the noise goes away while idling in gear but havent done it yet. I want to drain the oil and check the filter for any metal/fiber first.

Joe

I would lean to clutch plates and/or basket. Not saying your buddy did it, its just some parts that give up with normal wear and tear. Pull the clutch cover and the outer clutch hub off and take a look at the plates and the basket.

Padgett,

I just got the search working and there seems to be a ton of people with the same issue. I will try flipping the clutch steel plates first (Smooth Side of Stamping out) and go from there.

Joe

Padgett,

I just got the search working and there seems to be a ton of people with the same issue. I will try flipping the clutch steel plates first (Smooth Side of Stamping out) and go from there.

Joe

My guess is that will do nothing.

as GreyRacer is eluding to, this is a common issue. Most of us added some foam and a skidplate to muffle the sound. At least this is what you should hope for anyway.....is there a chance that your friend is a heavy clutch user and wore out your clutch?

There is a chance the clutch could be worn out but not by my friend. Hes been racing for 45 years but isnt abusive at all to the clutch. I rode the bike myself the on Thursday and honestly didnt notice the noise until I was done riding. He told me that it was the same for him. You at least dont notice the noise until you get back to the truck after riding. Until then, I think the oil is cool enough to suppress the noise. After its warmed up and idling you can hear it for sure.

this may sound stupid but is your helmet off when you are back at the truck? Also are you off the bike? these two things drastically change how the bike sounds.

99% of the time when i have my bike running i am sitting on it with my helmet on. it sounds like a whole different bike when you are next to it.

after riding everything is heated up high temp, including the clutch - check your plates and springs and here is a reach...but what oil are you using?

also how many hrs on the bike?

I noticed at as I pulled up to the bike stand. I was on the bike and in neutral. It was when I put the bike in neutral that I heard it first.

As far as the oil goes. I use Maxima. I do know that my friend changed the oil and it maybe to a different viscosity then I had used in the past.

Joe

It's classic gear rattle, by the sound of things. Read the link I posted.

I noticed at as I pulled up to the bike stand. I was on the bike and in neutral. It was when I put the bike in neutral that I heard it first.

As far as the oil goes. I use Maxima. I do know that my friend changed the oil and it maybe to a different viscosity then I had used in the past.

Joe

My new 09 does the same thing. I've tried a couple different oils and it made no difference. I normally run Maxima as well. I'm just learning to tune it out. Listen to other Yamahas in the pits. They're all noisy!

The previous owner (or dealer) installed a Hinson Clutch Basket and managed to only get the Clutch Hub torqued to less then finger tight! I will have to get a new locking tab as the previous one broke off its tabs! There doesnt appear to be anymore damage other then that!

They also managed to strip the bottom bolt on the oil filter housing. I have no idea what they did there but the bolt has a larger diameter shank but all of the threads are rounded off. Does this sound like the right type of bolt was used? I have never seen a larger shank with smaller threads other then a shoulder bolt and this isnt a typical shoulder bolt.

Joe

The loose nut would account for the noise being louder than it should have been, but you will still have the same sort of thing happen.

Regarding the oil filter bolt, that's the right bolt. The dealer will most likely have one. If the threads are damaged, use a Heli-Coil, or Time-Sert insert long enough to extend past the drain hole that intersects the threads (arrow). Failure to do so without blocking off the drain port will result in a loss of oil pressure:

well2.jpg?t=1208756212

For more on the causes and fixes for this, and a means of preventing it from ever happening:

http://www.thumpertalk.com/forum/showthread.php?t=575367

http://www.thumpertalk.com/forum/showthread.php?t=634724

Gray,

How much do these Time Sert Kits cost? I am guessing that you say to use the 10mm kit is that correct?

Joe

my 06 rattle since the day i got it when i release the clutch.

Ok,

Just took my new to me 09 out for my first little blast on it. I have a definite roaring sound that gets MUCH worse when I pull my clutch lever IN. Is this something I need to tear into to check the tightness of my hub nut maybe? Other than that maiden voyage was just as pleasurable as planned. Thanks!

Gray,

How much do these Time Sert Kits cost? I am guessing that you say to use the 10mm kit is that correct?

Joe

No idea on the current cost, but yes, you need an M6x1.0x10mm insert. Be sure you cut down with the drill/spot facer as deep as the lip on the insert is, so that the hole will be at least as deep as it currently is. Otherwise, the bolt shoulder may bottom before clamping the cover.

SInce my roar gets much louder and intense when I have my clutch lever pulled IN, is this something I need to look into for peace of mind or just live with?

Thanks

Sure about that? That would be a matter of some concern, actually

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