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vibration related nois


Guest burke

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Guest burke

I have noticed a new vibration noise. Normally I wouldn't be to worried but this one is loud and somewhat embarrasing at stop lights (sounds like the bike is coming apart). It only does it while stopped at lights with the clutch pulled in or while in neutral. Sometimes it will be fine for a few seconds then start up. The sound is like large metal plates rattling (it is not the clutch noise, that is quieter and I know what that sounds like now). It sounds like it is coming from the engine area but I guess it could be the pipes.

 

Anyone else have a really loud rattle/buzzing noise like this? (please no jokes about v-twins allways rattling, this is very loud and definitely not normal)

 

Anyone with after market pipes notice more rattle in the pipes now that the back pressure is reduced?

 

PS I did the drill mod to the pipes where you drill small holes in the end can but I did not remove any baffles or cut anything out. Could reduced backpressure because the 12 or so small holes be the cause?

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Are you still under warranty? If so...go in.

 

I don't have and haven't heard of any others with any problems with reduced back pressure causing this type noise. My rear signals vibrate more do to the louder pipes...that's about it.

 

The fact that it only does it with the clutch disengaged or neutral is concerning. And you did confirm that you know what the dry clutch is supposed to sounds like. Otherwise, I would get your metric tools out and make sure every nut/bolt/hex that you can see is tight (alternator cover, oil cooler, head pipes, crossover support...etc) Hopefully it's just something loose that vibrates at a certain harmonic.

 

Can you get a 2nd set of ears and have them help you locate the noise?

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Guest burke
Could be the pipe between the two headers.

49137[/snapback]

 

 

Japp, which pipe are you talking about. Mine only has the crossover down low by the sump. I could be wrong but it doesn't sound like an engine noise. In fact it sounds just like my STI when a baffle came loose in my muffler. From what I read of the exhaust forums I don't think there are any baffles that would sound like this in the end cans though.

 

I checked all of the common bolts (exhaust, headers etc...) and they are all tight. I did take off the california carbon cansiter and rebolted the bracket to the crossover but that is all tight....Or is it? I wonder if the rubber mounts are looser than normal becuase I only put in the one u shaped bracket and left the box off? The box was relatively thick and was mounted between the bracket and rubber mounts acting as a washer.....I will check this next.

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Guest burke

OK. It isn't the crossover. Now I am suspicious of the starter cover. It seems to be bolted to something that is zip tied or cable clamped to the starter. This allows the whole cover to rotate up and down but not come off. When it rotates it contacts the rear shock resevoir and I can see that they have been rubbing. Maybe this would be loud enough at the right resonant frequency to cause the noise.

 

Odd thing though, it only seems to do it when the bike is warm and it did seem to do it as I was letting out the clutch but it could be that that is when the whole bike vibrates the most (at this frequency), so it could still be external to the transmission. I would think that if it was a clutch problem I would see it at all frequencies and the noise would just change pitch.

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Probably not the starter cover- it's plastic. Two acorn nuts hold it on. But given that it is loose, definitely tighten it up and maybe use some blue locktite. A mess of hoses sets behind the starter....

 

If you think it might be mufflers, why not take them off and shake them? 20 minutes, tops.

What about the shifter linkage? If loose and un-lubricated, it could potentially rattle. :huh2:

 

Edit- I just remembered- isn't there a plate INSIDE the crossover? Could it have come unwelded? Is that a word?

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I can't offer a good solution, but my bike started a weird low freq vibration/rattle right after I fixed my shift return spring. It only made the noise when the engine RPM moved through the ~1000rpm range(such as slowing down to a light, or about to idle up and take off), and the fairing amplified the sound. It definitely came from down around the engine/transmission though, although I never could isolate it, and it of course NEVER did it unless I was ON the bike sitting in traffic :rolleyes:

 

I never did figure out what it was, and we'll see if it still exists when I get the bike back :huh2:

 

al

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I had a vibration noise similar to your description after installing my Stucchi x-over...turned out to be the bracket for the kickstand bracket was too close to pipe after the install and it was vibrating...did a little pry with a big screwdriver and it went away. :luigi: k

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Guest aironepony

My Bro In Laws SP3 had a rattle just like this. We found that the cross over box had a loose diverter inside it. It was manouvered back into place, a few radial holes were drilled in the tube section that housed it and it was welded back in position sealing the drilled hole in the process. Rattle gone!

 

Could it be similar problem I wonder?....... :thumbsup:

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Guest burke
I can't offer a good solution, but my bike started a weird low freq vibration/rattle right after I fixed my shift return spring.  It only made the noise when the engine RPM moved through the ~1000rpm range(such as slowing down to a light, or about to idle up and take off), and the fairing amplified the sound.  It definitely came from down around the engine/transmission though, although I never could isolate it, and it of course NEVER did it unless I was ON the bike sitting in traffic  :rolleyes:

 

I never did figure out what it was, and we'll see if it still exists when I get the bike back  :huh2:

 

al

49181[/snapback]

 

 

I noticed the same thing. If I stop somewhere and get off the bike to isolate the problem , it never seems to do it (lean angle ?). I was going to start striping things off last night to investigate but I noticed that my tranny seal where the shaft goes into the tranny is leaking oil when it gets hot. As my bike is under warranty until august, I decided not to touch it until I can get the seals replaced (under warranty).

 

I noticed for the first time yesterday that it does do it when I go to take off. So it is not only when sitting at idle but when engaging the clutch at low rpm also.

 

Let me know if you figure yours out. Before I figure mine.

 

Burke

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Guest burke

Still don't know the cause of the vibration noise. Will be taking bike into dealer tommorrow.

 

I have started to notice a shudder when engaging/disengaging the clutch (this shudder also causes the vibration, although I can get it to vibrate other times as well) when the engine is hot.

 

I also had a clutch slip. I was riding along and the engine just started to rev, then the clutch caught again and jerked the bike (a little disconcerting). Only did it once though.

 

Last but not least when shifting from 2nd to 3rd sometimes it won't go into gear and when shifting from 3rd to 2nd sometimes it drops all the way into neutral (which sucks when you are counting on engine braking to slow you down a little).

 

Burke

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Still don't know the cause of the vibration noise.  Will be taking bike into dealer tommorrow. 

 

I have started to notice a shudder when engaging/disengaging the clutch (this shudder also causes the vibration, although I can get it to vibrate other times as well) when the engine is hot.

 

I also had a clutch slip.  I was riding along and the engine just started to rev, then the clutch caught again and jerked the bike (a little disconcerting).  Only did it once though.

 

49395[/snapback]

 

Classic symptoms of a clutch plate coming apart. Have the dealer check the rear main seal while he's in there.

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I sent my '03 V11 Sport down to MPH in Houston for a ticking noise that sounded like valve noise, but loud. Mike Haven has told me that when the engine was examined, he found a bad connecting rod bearing was making the noise. Just on one side, wierd, but under warranty. Bike had 2k miles on it. While it is there they are going through everything to make sure the bike is sound. Had some clicking noises from the rear of the bike begin prior to the engine noise problem. Love the bike though and bought a Nero Corsa from MPH as second Guzzi.

 

Wick

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Guest burke

The dealer called back and of course they said there was nothing wrong with the bike. They didn't even have a problem shifting. I know how to shift a bike and there are times when I have to lift my entire leg to get it to shift into third (and I'm a big guy). If I try to shift any harder I will break something. They said it didn't do it at all and that they didn't want to open it up and look because the procedure was too involved for something that they obviously don't believe is real. They also told me not to worry about the oil leak as it is not severe and not leaking that much.

 

They did mention that the engine number on my engine is hand engraved and not stamped. They thought this was abnormal. Anyone know if this is the case? They were going to call moto international and find out what the deal is with this bike.

 

I'll keep you updated on what they find.

 

Burke

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