Author Topic: Strange noise  (Read 12511 times)

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scoTTy

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on: August 23, 2007, 03:26:05 pm
This just started,, just before I shift to the next gear any gear.. I hear this vibration like noise,

It dissappears after I get past a certain RPM level.. the re occurs at the same spot in the next gears.

Almost sounds like something is loose and hitting .. I can't tell where it's coming from since it doesn't last long.

It only does it while moving..I haved revved the enginge slowly on the center stand,  but it doesn't occur.

The rear chain is within tolerance, It doesn't sound like valves, I thought about pulling the primary cover and checking to see if the primary chain is loose, but I tightened it about 75 miles ago.

Has anyone any suggestions on where to begin My search,,

Thanks,

I'll check back later, I've got to get to work,,

scotty


justin_o_guy

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Reply #1 on: August 23, 2007, 06:56:43 pm
I had a buzz/rattle on the Guzzi that wouldn't do it sitting still & revving the engine & wouldn't do it engine off coasting down the rough, gravel drive. Went over the bike closely & found a loose spline connector in the shift linkage.


Thumper

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Reply #2 on: August 23, 2007, 07:18:25 pm
Exhaust brackets or clamps? Other brackets? My turn signals develop harmonic resonance at certain RPMs....


RagMan

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Reply #3 on: August 23, 2007, 08:10:50 pm
I agree, fender stays, turn signals, headlight housing etc are all capable of having harmonic sympathy with engine revs.  Depending on the tone of the vibration can give you a clue to the location. Is it high pitched, tinny sound, or a deeper tone.  High pitched is usually caused by something short, lower tones by something longer.
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deejay

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Reply #4 on: August 23, 2007, 09:40:51 pm
This just started,, just before I shift to the next gear any gear.. I hear this vibration like noise,

It dissappears after I get past a certain RPM level.. the re occurs at the same spot in the next gears.

Almost sounds like something is loose and hitting .. I can't tell where it's coming from since it doesn't last long.

It only does it while moving..I haved revved the enginge slowly on the center stand,  but it doesn't occur.

The rear chain is within tolerance, It doesn't sound like valves, I thought about pulling the primary cover and checking to see if the primary chain is loose, but I tightened it about 75 miles ago.

Has anyone any suggestions on where to begin My search,,

Thanks,

I'll check back later, I've got to get to work,,

scotty


Is it a rattle/clanging noise? I'm willing to put money on this if you still have the stock exhaust pipe... SAME EXACT thing happened to my bike. There is a botched cat converter welded inside the exhaust, it was rattling in my head pipe at certain rpms. I took off the silencer and used a metal hole saw for a drill and removed it in 2 minutes. Never rattled again, did a plug chop after i removed it, and didn't need to rejet. It bugged the hell outta me for 500 miles, took me that long to figure it out.


scoTTy

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Reply #5 on: August 24, 2007, 12:46:37 am
this is really driving me batty....I went out and bought a new auto engine stethoscope,mine had dry rotted after 40 years.. still can't pinpoint it and I can get the sound when I rev high enough sitting still .

sounds like ball bearings in a tin can.. kinda of high pitched.. got 2 fans on the engine in the garage.. will check the valves again when it cools down.. yet when I put the scope on the valves it doesn't have that hig frequency rattle..rather quiet matter of fact.. seems like it coming from the front.. can't tell.. I did not check the eccentric cam when I did the 300 mile check.. would this be a possibility.. It only occurs in a small rpm range.. the stethoscope is relatively useless since everything is mechanical.. It seems It might be behind the timing cover.. but I can't tell.. aaAaRgH




deejay

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Reply #6 on: August 24, 2007, 12:51:05 am
do you have the stock exhaust system on there???


scoTTy

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Reply #7 on: August 24, 2007, 01:04:54 am
Yes I do deejay and I read where you said that was where you pinpointed your noise.. I will check that.. You also said you did a plug chop.. what is that?

thanks for your quick reply

scotty


bwilson17

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Reply #8 on: August 24, 2007, 01:34:58 am
I once had a strange vibration sound when the engine was higher RPM when shifting then went away when the RPM went down. I tightened all the engine mount bolts and the bolts that held the gas tank in place - That solved my problem.


deejay

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Reply #9 on: August 24, 2007, 01:36:34 am
Yes I do deejay and I read where you said that was where you pinpointed your noise.. I will check that.. You also said you did a plug chop.. what is that?

thanks for your quick reply

scotty

After I took out the cat converter, i tested to make sure I wasn't running too lean due to removing it. A chop is when you install a new spark plug, get the rpms up and kill the engine under load. then you pull the plug on the side of the road to see if the color is good. It's a great way to see if you are running rich or lean.


scoTTy

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Reply #10 on: August 24, 2007, 01:48:07 am
Thanks BW.. I'll go check the bolts again since I've had the tank off many times..

and thanks again deejay for your info.. I did notice the rod that holds the footpegs on was awful close to the header.. so I backed it off and then tightened the other side,,

I'll find it or blow it up in the process.. I do have a years warranty if i recall ;) :D ;D


gapl53

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Reply #11 on: August 24, 2007, 03:37:53 pm
I have a buzzing vibration in my Electra-X just as I start to disengage the clutch. This happens only at mid-RPMs. Checked everything found nothing wrong. Decided that it was a harmonic vibration when pressure starts to be removed from the clutch plates and they slip.
Also if the last item that was adjusted was the primary chain before this started, I would start my search there.


No. 5

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Reply #12 on: August 31, 2007, 01:51:51 pm
My Bike developed a rattle like you describe. I thought it was the valves too, but the more I heard it the more it sounded outside. Went right for the chassis, exhaust and engine stuff. (maybe a loose traficator?) Turns out the vibration dampener weights were loose in the handle bars. Voila!


rpnix

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Reply #13 on: August 31, 2007, 02:07:48 pm
Another place to look is the chains. I had an odd "playing card in the spokes" noise whenever I backed off the throttle. Turned out that the chains needed to be tightened.
Bob Nix -- '06 Ural Tourist, '07 Royal Enfield Electra  <-- Click on the bike to see photos!


Kevin Mahoney

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Reply #14 on: September 01, 2007, 09:05:01 am
Sometimes the best cure for a noise in the Bullet is a louder muffler.
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