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Discussion Starter · #1 ·
I'm new to these bikes & dont know what sounds are normal or not.First at 60mph 5th gear I notice a cyclic type sound at about 1 sec intervals.Its like a high pithed hum & goes away or lessens above & below this speed.

The other noise I hear is a rattle at idle that goes away as you release the clutch in gear,I think maybe its just countershaft gear chatter & is normal I hope.

I'm hoping all these are normal .the bike has 34000km on it & there is no indication of anything abnormal in the oil.thanks for any info
 

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. . . at 60mph 5th gear I notice a cyclic type sound at about 1 sec intervals.Its like a high pitched hum & goes away or lessens above & below this speed. . . . I'm hoping all these are normal


I have a very similar hum on my '82 GL500I, but I've not attributed it to a speed yet. I'll make some runs tomorrow to get more data.



If it's not "normal", at least it's got company.
 

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The chatter could possibly be the crappy worn springs in the clutch pressure plate. The springs on are used as a means of dampening vibration for the clutch. The only easy way to replace them is a new clutch basket.... Which is expensive.



Now I've also noticed earlier CX's don't have the springs and are solid. But there is a extended piece of metal so I don't think you can use them on all CX engines.
 

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At that mileage and if the bike has been reasonably well kept and if you are going to keep the bike then I would plan to return it to a great serviceable state come the end of the,"Season".



These sounds can be hard to track down so just go through the bike.



Replace all wheel bearings(Dead cheap) but you may need to make a little tool to take the locking rings out.The bearings used front and back are the same for all none turbo GL/CX500 models e.g RS 6302



http://cgi.ebay.com/2-6302-2RS-New-...394?pt=LH_DefaultDomain_0&hash=item5ad8a095c2



Dress the clutch ,



http://cx500forum.com/index.php?/to..._hl__+clutch++noise__fromsearch__1#entry10691



Dress and reset tappets,



http://www.sheppola.karoo.net/TwistedTwin/TappetsDressing.htm



Check Fan Guard and Fan condition,



http://cx500forum.com/index.php?/to...p__10252__hl__noise__fromsearch__1#entry10252



Drain and re-fill the Rear transmission/Drive box and grease up.



http://www.pdsrecording.site90.com/cxgl500/OilChange.htm



The bikes will not have been serviced properly for a long time in most cases and these jobs are not hard for the home mechanic.Doing this and the bike are easily capable of well over 150,000 miles+ with very few problems.



http://globalcxglvtwins.hostingdelivered.com/viewtopic.php?f=20&t=289





Some engine sounds,



http://www.pdsrecording.site90.com/cxgl500/noises.htm



http://www.youtube.com/watch?v=xcu3veeQolo



 

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I have had a couple of mystery rattles in the past.



One was a loose baffle that had rusted loose inside the muffler. It didn't even rattle when I took the muffler off, only when I put a rod inside did I find that it was loose. A new muffler fixed that one. It only made noise in a certain rpm range.



The other one was also hard to pinpoint and it was the radiator guard on the front of the radiator.It would only rattle at a certain rpm when the fan was sucking at a certain rate and then went away at a higher speeds when the wind pushed it tight. I solved that one by putting a piece of cloth on the tabs that go into the slot at the top of the guard. That made it tight all the time and the rattle went away. It too sounded like a bad clutch, but it wasn't.



Let us know what you find ...
 

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...a cyclic type sound at about 1 sec intervals.Its like a high pithed hum & goes away or lessens above & below this speed.


The 81 GL500I in the avitar made the same rythymic sound between 4000-6000 rpm. I asked about it on the Australian forum and Doc Green said this -



"There is no doubt that this question may provide some interesting theories about your rhythmic beat. With out getting deep into the wonders of science the beat you are describing is based on a factor called "harmonics" (frequency pulsations) that are created from ,1, the number of engine rev's, 2, the number of cylinders, 3, the number of degrees that separate the firing strokes, 4, the balance of the engine, 5, the type or configuration of the exhaust. There are other factors affecting this "beat" that go beyond my brain capacity. Basically put all of the above into your engine and providing that all is well mechanically in your engine, you have your own rhythmic beat, that is quite often not repeated in machines of the same type and model."



That was 10K miles ago, it still sounds the same and the bike runs beautifully.
 

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I can't stand a bike that rattles. I get a new one about once a month. While you're riding try touching stuff to see if the sound changes. You can also rev it up on the centerstand to track some things down. I've gone over the bike tapping stuff with a stick and tightening or insulating things that rattle. Sometimes it takes a while to find the source of a new noise.
 

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Discussion Starter · #10 ·
Well what a great response.thank you all for your great info.I have gone thru this bike entirely from the frame up,but thats not to say I didn't miss something.I tried tightening the grille as suggested but no diff.I noticed tonight that the noise is louder on the left side sitting on the bike & speed doesn't matter it happens at around 5000rpm,& as strange as this may sound but it actually sounds like crickets,like a high pitched chittering sound.

(yes I did check & no crickets stuck in the rad) :lol:If I pull the clutch lever in at 60mph & let her idle the noise goes away which tells me its from the engine.

I was thinking the same gopher that it's just engine harmonics or at least I would like to think thats all it is.

The noise at idle I think it is the clutch as you have suggested I will double check with a stethescope but its very minor.Thank you all again & I feel better knowing that some of you have the same issue & its the nature of the beast.I will keep monitoring it & let you know if I find something
 

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Well what a great response.thank you all for your great info.I have gone thru this bike entirely from the frame up,but thats not to say I didn't miss something.I tried tightening the grille as suggested but no diff.I noticed tonight that the noise is louder on the left side sitting on the bike & speed doesn't matter it happens at around 5000rpm,& as strange as this may sound but it actually sounds like crickets,like a high pitched chittering sound.

(yes I did check & no crickets stuck in the rad) :lol:If I pull the clutch lever in at 60mph & let her idle the noise goes away which tells me its from the engine.

I was thinking the same gopher that it's just engine harmonics or at least I would like to think thats all it is.

The noise at idle I think it is the clutch as you have suggested I will double check with a stethescope but its very minor.Thank you all again & I feel better knowing that some of you have the same issue & its the nature of the beast.I will keep monitoring it & let you know if I find something


Remember also that sounds with a helmet on are distorted and may be incorrectly amplified making it hard to diagnose them.
 

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Discussion Starter · #12 ·
Great point Shep funny you say that.

I had a different helmet on today & it didnt sound as bad .

Who knows maybe its all in me head
 

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There is a rhythmic hum from most V-twins as certain revs/road speeds.It's part of their charm.I can really hear it when I go through some quiet villages over here that have very narrow streets and the sound of the exhausts and engine reverberate against the shop windows
 

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Don't know if this has anything to do with your noises, but my 82 GL is noisy for lack of a better description. When I bought mine, my friend at the salvage yard I frequent was quick to chime in. He said, "great bike, indestructable engine, but with the fairing you'll hear a lot of engine noise that you wouldn't hear on a CX." When I got it running, he was right. The fairing seems to amplify an already "noisy" engine. Fan whir, gear box noise, etc. Make sure all the basic maintenance is done and done right, valve adjustment, carb sync, cam chain tension. I took my fairing off and rode it around the airport up to about 50 MPH and 90% of the noises on mine were gone. The fairing seems to act like a sound chamber. I had one noise that I found annoying at different RPM's, found the front radiator shroud rattled at certain RPM's. Fixed that easily. If anything is noticably loud or metallic sounding, dig deeper. Or if your "normal" engines sounds change or get louder, look for something mechanical. And you're clutch chatter may go away with a good carb sync. Most honda's clutches from this era will chatter at idle if out of sync.
 

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Thanks for that Shep, I didn't know that.

"quiet villages" ? Rattling windows, driving the prams off the road.. still think you're a motorcycle hooligan.
 

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That was interesting. No doubt the narrow trough formed by the 2 and 3 story buildings with the pavement contains and reflects sound. Yorkersgate especially. The streets are much tidier for litter than they are here.
I highjacked again..sorry OU812
 

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I wear earplugs and don't hear anything. I bought a GL500 new and it always made all kinds of noises from day one. I rode it for 15 years like that. At 6000 to 7000 RPMS everything makes noise.
 

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Discussion Starter · #20 ·
Just wondering would the fan set up this cyclic noise.seems to be up front.This is a new fan as the old one was showing some small cracks,better safe that sorry.I just wonder if anyone that has done the electric fan conversion notes this noise.Funny it doesn't seem to be rattling anymore at idle,the bike has sat for three years & I think it's starting to reseat everything where it should be so thats good.I really like this forum,everyone is very helpfull thank you
 
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